m1une's library

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:heavy_check_mark: verify/game/game_algorithms.test.cpp

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Code

#define PROBLEM "https://judge.yosupo.jp/problem/aplusb"

#include "../../game/all.hpp"

#include <algorithm>
#include <cassert>
#include <cstdint>
#include "../../utilities/fast_io.hpp"
#include <random>
#include <vector>

namespace {

using m1une::game::GameOutcome;

void test_nim() {
    std::vector<int> empty;
    assert(m1une::game::nim_sum(empty) == 0);
    assert(!m1une::game::nim_first_player_wins(empty));
    assert(m1une::game::misere_nim_first_player_wins(empty));

    std::vector<int> ordinary = {1, 4, 5};
    assert(m1une::game::nim_sum(ordinary) == 0);
    assert(!m1une::game::nim_first_player_wins(ordinary));

    std::vector<int> one_one = {1, 1};
    std::vector<int> one_one_one = {1, 1, 1};
    assert(m1une::game::misere_nim_first_player_wins(one_one));
    assert(!m1une::game::misere_nim_first_player_wins(one_one_one));

    std::vector<int> general = {1, 2, 3};
    assert(!m1une::game::misere_nim_first_player_wins(general));

    for (int code = 0; code < 625; ++code) {
        int remaining = code;
        std::vector<int> heaps(4);
        for (int& heap : heaps) {
            heap = remaining % 5;
            remaining /= 5;
        }

        auto ordinary_move = m1une::game::nim_winning_move(heaps);
        assert(bool(ordinary_move) == m1une::game::nim_first_player_wins(heaps));
        if (ordinary_move) {
            assert(0 <= ordinary_move->heap && ordinary_move->heap < 4);
            assert(ordinary_move->new_size < heaps[ordinary_move->heap]);
            heaps[ordinary_move->heap] = ordinary_move->new_size;
            assert(!m1une::game::nim_first_player_wins(heaps));
        }

        remaining = code;
        for (int& heap : heaps) {
            heap = remaining % 5;
            remaining /= 5;
        }
        const bool has_stone = std::any_of(
            heaps.begin(),
            heaps.end(),
            [](int heap) { return heap != 0; }
        );
        auto misere_move = m1une::game::misere_nim_winning_move(heaps);
        assert(
            bool(misere_move)
            == (has_stone && m1une::game::misere_nim_first_player_wins(heaps))
        );
        if (misere_move) {
            assert(0 <= misere_move->heap && misere_move->heap < 4);
            assert(misere_move->new_size < heaps[misere_move->heap]);
            heaps[misere_move->heap] = misere_move->new_size;
            assert(!m1une::game::misere_nim_first_player_wins(heaps));
        }
    }
}

std::vector<int> naive_grundy(const std::vector<std::vector<int>>& graph) {
    const int size = int(graph.size());
    std::vector<int> result(size);
    for (int vertex = size - 1; vertex >= 0; --vertex) {
        std::vector<bool> appears(size + 1);
        for (int next : graph[vertex]) appears[result[next]] = true;
        while (appears[result[vertex]]) result[vertex]++;
    }
    return result;
}

void test_grundy_random() {
    std::mt19937 random(123456789);
    for (int size = 0; size <= 40; ++size) {
        for (int trial = 0; trial < 100; ++trial) {
            std::vector<std::vector<int>> graph(size);
            for (int from = 0; from < size; ++from) {
                for (int to = from + 1; to < size; ++to) {
                    if (random() % 5 == 0) graph[from].push_back(to);
                }
            }
            assert(m1une::game::grundy_numbers(graph) == naive_grundy(graph));
        }
    }
}

std::vector<GameOutcome> naive_outcomes(
    const std::vector<std::vector<int>>& graph
) {
    const int size = int(graph.size());
    std::vector<GameOutcome> result(size, GameOutcome::Draw);
    std::vector<bool> decided(size);
    for (int vertex = 0; vertex < size; ++vertex) {
        if (graph[vertex].empty()) {
            result[vertex] = GameOutcome::Lose;
            decided[vertex] = true;
        }
    }

    bool changed = true;
    while (changed) {
        changed = false;
        for (int vertex = 0; vertex < size; ++vertex) {
            if (decided[vertex]) continue;
            bool has_losing_move = false;
            bool all_moves_win = true;
            for (int next : graph[vertex]) {
                has_losing_move |= decided[next] && result[next] == GameOutcome::Lose;
                all_moves_win &= decided[next] && result[next] == GameOutcome::Win;
            }
            if (has_losing_move || all_moves_win) {
                result[vertex] = has_losing_move ? GameOutcome::Win : GameOutcome::Lose;
                decided[vertex] = true;
                changed = true;
            }
        }
    }
    return result;
}

void test_retrograde_random() {
    std::mt19937 random(987654321);
    for (int size = 0; size <= 30; ++size) {
        for (int trial = 0; trial < 100; ++trial) {
            std::vector<std::vector<int>> graph(size);
            for (int from = 0; from < size; ++from) {
                for (int to = 0; to < size; ++to) {
                    if (random() % 8 == 0) graph[from].push_back(to);
                }
            }
            auto actual = m1une::game::retrograde_analysis(graph);
            assert(actual.outcome == naive_outcomes(graph));
            for (int vertex = 0; vertex < size; ++vertex) {
                assert((actual.distance[vertex] == -1)
                       == (actual.outcome[vertex] == GameOutcome::Draw));
                if (actual.outcome[vertex] == GameOutcome::Draw) {
                    assert(actual.move[vertex] != -1);
                    assert(actual.outcome[actual.move[vertex]] == GameOutcome::Draw);
                } else if (graph[vertex].empty()) {
                    assert(actual.outcome[vertex] == GameOutcome::Lose);
                    assert(actual.distance[vertex] == 0);
                    assert(actual.move[vertex] == -1);
                } else {
                    assert(
                        std::find(
                            graph[vertex].begin(),
                            graph[vertex].end(),
                            actual.move[vertex]
                        ) != graph[vertex].end()
                    );
                    if (actual.outcome[vertex] == GameOutcome::Win) {
                        assert(
                            actual.outcome[actual.move[vertex]]
                            == GameOutcome::Lose
                        );
                        int best = size + 1;
                        for (int next : graph[vertex]) {
                            if (actual.outcome[next] == GameOutcome::Lose) {
                                best = std::min(best, actual.distance[next] + 1);
                            }
                        }
                        assert(actual.distance[vertex] == best);
                    } else {
                        assert(
                            actual.outcome[actual.move[vertex]]
                            == GameOutcome::Win
                        );
                        int best = 0;
                        for (int next : graph[vertex]) {
                            best = std::max(best, actual.distance[next] + 1);
                        }
                        assert(actual.distance[vertex] == best);
                    }
                    assert(
                        actual.distance[vertex]
                        == actual.distance[actual.move[vertex]] + 1
                    );
                }
            }
        }
    }

    std::vector<std::vector<int>> chain(5);
    chain[0].push_back(1);
    chain[1].push_back(2);
    chain[2].push_back(3);
    chain[3].push_back(4);
    auto result = m1une::game::retrograde_analysis(chain);
    for (int vertex = 0; vertex < 5; ++vertex) {
        assert(result.distance[vertex] == 4 - vertex);
    }
}

}  // namespace

int main() {
    m1une::utilities::FastInput fast_input;
    m1une::utilities::FastOutput fast_output;

    test_nim();
    test_grundy_random();
    test_retrograde_random();

    long long first, second;
    fast_input >> first >> second;
    fast_output << first + second << '\n';
}
#line 1 "verify/game/game_algorithms.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/aplusb"

#line 1 "game/all.hpp"



#line 1 "game/green_hackenbush.hpp"



#include <cassert>
#include <cstdint>
#include <vector>

namespace m1une {
namespace game {

// Every vertex represents one green edge. parent[v] == -1 attaches that edge
// to the ground; otherwise it attaches it above the edge parent[v].
inline uint64_t green_hackenbush_grundy(const std::vector<int>& parent) {
    const int size = int(parent.size());
    std::vector<std::vector<int>> children(size);
    std::vector<int> roots;
    for (int edge = 0; edge < size; ++edge) {
        assert(-1 <= parent[edge] && parent[edge] < size);
        assert(parent[edge] != edge);
        if (parent[edge] == -1) {
            roots.push_back(edge);
        } else {
            children[parent[edge]].push_back(edge);
        }
    }

    std::vector<int> order = roots;
    order.reserve(size);
    for (int position = 0; position < int(order.size()); ++position) {
        const int edge = order[position];
        for (int child : children[edge]) order.push_back(child);
    }
    assert(int(order.size()) == size);

    std::vector<uint64_t> branch(size);
    for (int position = size - 1; position >= 0; --position) {
        const int edge = order[position];
        uint64_t children_grundy = 0;
        for (int child : children[edge]) children_grundy ^= branch[child];
        branch[edge] = children_grundy + 1;
    }

    uint64_t result = 0;
    for (int root : roots) result ^= branch[root];
    return result;
}

inline bool green_hackenbush_first_player_wins(
    const std::vector<int>& parent
) {
    return green_hackenbush_grundy(parent) != 0;
}

}  // namespace game
}  // namespace m1une


#line 1 "game/grundy.hpp"



#line 5 "game/grundy.hpp"
#include <queue>
#line 7 "game/grundy.hpp"

namespace m1une {
namespace game {

// graph[v] contains the states reachable from v in one move.
// The graph must be a DAG.
template <typename Graph>
std::vector<int> grundy_numbers(const Graph& graph) {
    const int size = int(graph.size());
    std::vector<int> indegree(size);
    for (int vertex = 0; vertex < size; ++vertex) {
        for (int next : graph[vertex]) {
            assert(0 <= next && next < size);
            indegree[next]++;
        }
    }

    std::queue<int> queue;
    for (int vertex = 0; vertex < size; ++vertex) {
        if (indegree[vertex] == 0) queue.push(vertex);
    }
    std::vector<int> order;
    order.reserve(size);
    while (!queue.empty()) {
        const int vertex = queue.front();
        queue.pop();
        order.push_back(vertex);
        for (int next : graph[vertex]) {
            if (--indegree[next] == 0) queue.push(next);
        }
    }
    assert(int(order.size()) == size);

    std::vector<int> grundy(size);
    std::vector<int> seen(size + 1, -1);
    for (int position = size - 1; position >= 0; --position) {
        const int vertex = order[position];
        for (int next : graph[vertex]) {
            const int value = grundy[next];
            if (value <= size) seen[value] = vertex;
        }
        while (grundy[vertex] <= size && seen[grundy[vertex]] == vertex) {
            grundy[vertex]++;
        }
    }
    return grundy;
}

}  // namespace game
}  // namespace m1une


#line 1 "game/minimax.hpp"



#line 6 "game/minimax.hpp"
#include <utility>
#line 8 "game/minimax.hpp"

namespace m1une {
namespace game {

template <typename T>
struct MinimaxResult {
    std::vector<T> value;
    std::vector<int> move;
};

template <typename T>
MinimaxResult<T> dag_minimax(
    const std::vector<std::vector<int>>& graph,
    const std::vector<T>& terminal_value,
    const std::vector<bool>& maximize
) {
    const int size = int(graph.size());
    assert(int(terminal_value.size()) == size);
    assert(int(maximize.size()) == size);

    std::vector<int> indegree(size);
    for (int vertex = 0; vertex < size; ++vertex) {
        for (int next : graph[vertex]) {
            assert(0 <= next && next < size);
            indegree[next]++;
        }
    }

    std::queue<int> queue;
    for (int vertex = 0; vertex < size; ++vertex) {
        if (indegree[vertex] == 0) queue.push(vertex);
    }
    std::vector<int> order;
    order.reserve(size);
    while (!queue.empty()) {
        const int vertex = queue.front();
        queue.pop();
        order.push_back(vertex);
        for (int next : graph[vertex]) {
            if (--indegree[next] == 0) queue.push(next);
        }
    }
    assert(int(order.size()) == size);

    std::vector<T> value = terminal_value;
    std::vector<int> move(size, -1);
    for (int position = size - 1; position >= 0; --position) {
        const int vertex = order[position];
        if (graph[vertex].empty()) {
            value[vertex] = terminal_value[vertex];
            continue;
        }

        move[vertex] = graph[vertex][0];
        value[vertex] = value[move[vertex]];
        for (int next : graph[vertex]) {
            const bool improves = maximize[vertex]
                                      ? value[vertex] < value[next]
                                      : value[next] < value[vertex];
            if (improves) {
                value[vertex] = value[next];
                move[vertex] = next;
            }
        }
    }
    return {std::move(value), std::move(move)};
}

}  // namespace game
}  // namespace m1une


#line 1 "game/nim.hpp"



#include <iterator>
#include <optional>
#include <type_traits>
#line 8 "game/nim.hpp"

namespace m1une {
namespace game {

template <typename T>
struct NimMove {
    int heap;
    T new_size;
};

template <typename Iterator>
auto nim_sum(Iterator first, Iterator last) {
    using T = typename std::iterator_traits<Iterator>::value_type;
    T result{};
    while (first != last) {
        result ^= *first;
        ++first;
    }
    return result;
}

template <typename Range>
auto nim_sum(const Range& heaps) {
    using std::begin;
    using std::end;
    return nim_sum(begin(heaps), end(heaps));
}

template <typename Range>
bool nim_first_player_wins(const Range& heaps) {
    return nim_sum(heaps) != 0;
}

template <typename Range>
auto nim_winning_move(const Range& heaps) {
    using std::begin;
    using std::end;
    using T = std::decay_t<decltype(*begin(heaps))>;

    const T sum = nim_sum(heaps);
    if (sum == 0) return std::optional<NimMove<T>>{};
    int index = 0;
    for (
        auto iterator = begin(heaps);
        iterator != end(heaps);
        ++iterator, ++index
    ) {
        const T new_size = *iterator ^ sum;
        if (new_size < *iterator) return std::optional(NimMove<T>{index, new_size});
    }
    return std::optional<NimMove<T>>{};
}

template <typename Range>
bool misere_nim_first_player_wins(const Range& heaps) {
    using std::begin;
    using std::end;

    auto first = begin(heaps);
    const auto last = end(heaps);
    bool odd_nonzero_heaps = false;
    bool has_large_heap = false;
    using T = typename std::iterator_traits<decltype(first)>::value_type;
    T sum{};
    for (; first != last; ++first) {
        sum ^= *first;
        if (*first != 0) {
            odd_nonzero_heaps = !odd_nonzero_heaps;
        }
        if (*first > 1) has_large_heap = true;
    }
    return has_large_heap ? sum != 0 : !odd_nonzero_heaps;
}

template <typename Range>
auto misere_nim_winning_move(const Range& heaps) {
    using std::begin;
    using std::end;
    using T = std::decay_t<decltype(*begin(heaps))>;

    T sum{};
    int ones = 0;
    int large_heaps = 0;
    int only_large_heap = -1;
    int index = 0;
    for (
        auto iterator = begin(heaps);
        iterator != end(heaps);
        ++iterator, ++index
    ) {
        sum ^= *iterator;
        if (*iterator == 1) ones++;
        if (*iterator > 1) {
            large_heaps++;
            only_large_heap = index;
        }
    }

    if (large_heaps == 0) {
        if (ones == 0 || ones % 2 == 1) return std::optional<NimMove<T>>{};
        index = 0;
        for (
            auto iterator = begin(heaps);
            iterator != end(heaps);
            ++iterator, ++index
        ) {
            if (*iterator == 1) return std::optional(NimMove<T>{index, T(0)});
        }
    }
    if (large_heaps == 1) {
        const T new_size = ones % 2 == 0 ? T(1) : T(0);
        return std::optional(NimMove<T>{only_large_heap, new_size});
    }
    if (sum == 0) return std::optional<NimMove<T>>{};

    index = 0;
    for (auto iterator = begin(heaps); iterator != end(heaps); ++iterator, ++index) {
        const T new_size = *iterator ^ sum;
        if (new_size < *iterator) return std::optional(NimMove<T>{index, new_size});
    }
    return std::optional<NimMove<T>>{};
}

}  // namespace game
}  // namespace m1une


#line 1 "game/nim_product.hpp"



#include <array>
#line 7 "game/nim_product.hpp"
#include <limits>

namespace m1une {
namespace game {
namespace internal {

inline uint64_t nim_product_small(uint64_t x, uint64_t y) {
    if (x < 2 || y < 2) return x * y;

    int shift = 1;
    const uint64_t largest = x | y;
    while ((uint64_t(1) << (shift * 2)) <= largest) shift *= 2;
    const uint64_t mask = (uint64_t(1) << shift) - 1;
    const uint64_t x_high = x >> shift;
    const uint64_t x_low = x & mask;
    const uint64_t y_high = y >> shift;
    const uint64_t y_low = y & mask;

    const uint64_t high_product = nim_product_small(x_high, y_high);
    const uint64_t low_product = nim_product_small(x_low, y_low);
    const uint64_t mixed_product =
        nim_product_small(x_high ^ x_low, y_high ^ y_low);
    return ((mixed_product ^ low_product) << shift) ^ low_product
           ^ nim_product_small(high_product, uint64_t(1) << (shift - 1));
}

inline const std::array<uint8_t, 1 << 16>& nim_product_8_table() {
    static const auto table = [] {
        std::array<uint8_t, 1 << 16> result{};
        for (int x = 0; x < 256; ++x) {
            for (int y = 0; y < 256; ++y) {
                result[(x << 8) | y] = uint8_t(nim_product_small(x, y));
            }
        }
        return result;
    }();
    return table;
}

inline uint64_t nim_product_8(uint64_t x, uint64_t y) {
    return nim_product_8_table()[(x << 8) | y];
}

template <int Bits>
inline uint64_t nim_product_fixed(uint64_t x, uint64_t y) {
    if constexpr (Bits == 8) {
        return nim_product_8(x, y);
    } else {
        constexpr int shift = Bits / 2;
        constexpr uint64_t mask = (uint64_t(1) << shift) - 1;
        const uint64_t x_high = x >> shift;
        const uint64_t x_low = x & mask;
        const uint64_t y_high = y >> shift;
        const uint64_t y_low = y & mask;

        const uint64_t high_product =
            nim_product_fixed<shift>(x_high, y_high);
        const uint64_t low_product = nim_product_fixed<shift>(x_low, y_low);
        const uint64_t mixed_product = nim_product_fixed<shift>(
            x_high ^ x_low,
            y_high ^ y_low
        );
        return ((mixed_product ^ low_product) << shift) ^ low_product
               ^ nim_product_fixed<shift>(
                   high_product,
                   uint64_t(1) << (shift - 1)
               );
    }
}

}  // namespace internal

inline uint64_t nim_product(uint64_t x, uint64_t y) {
    return internal::nim_product_fixed<64>(x, y);
}

inline uint64_t nim_power(uint64_t base, uint64_t exponent) {
    uint64_t result = 1;
    while (exponent != 0) {
        if (exponent & 1) result = nim_product(result, base);
        base = nim_product(base, base);
        exponent >>= 1;
    }
    return result;
}

inline uint64_t nim_inverse(uint64_t value) {
    assert(value != 0);
    return nim_power(value, std::numeric_limits<uint64_t>::max() - 1);
}

inline uint64_t nim_quotient(uint64_t numerator, uint64_t denominator) {
    assert(denominator != 0);
    return nim_product(numerator, nim_inverse(denominator));
}

}  // namespace game
}  // namespace m1une


#line 1 "game/partisan_game.hpp"



#line 7 "game/partisan_game.hpp"

namespace m1une {
namespace game {

enum class PartisanOutcome { Left, Right, Next, Previous };

inline std::vector<PartisanOutcome> partisan_outcomes(
    const std::vector<std::vector<int>>& left_moves,
    const std::vector<std::vector<int>>& right_moves
) {
    const int size = int(left_moves.size());
    assert(int(right_moves.size()) == size);

    std::vector<int> indegree(size);
    for (int vertex = 0; vertex < size; ++vertex) {
        for (int next : left_moves[vertex]) {
            assert(0 <= next && next < size);
            indegree[next]++;
        }
        for (int next : right_moves[vertex]) {
            assert(0 <= next && next < size);
            indegree[next]++;
        }
    }

    std::queue<int> queue;
    for (int vertex = 0; vertex < size; ++vertex) {
        if (indegree[vertex] == 0) queue.push(vertex);
    }
    std::vector<int> order;
    order.reserve(size);
    while (!queue.empty()) {
        const int vertex = queue.front();
        queue.pop();
        order.push_back(vertex);
        for (int next : left_moves[vertex]) {
            if (--indegree[next] == 0) queue.push(next);
        }
        for (int next : right_moves[vertex]) {
            if (--indegree[next] == 0) queue.push(next);
        }
    }
    assert(int(order.size()) == size);

    std::vector<bool> left_wins_moving(size);
    std::vector<bool> left_wins_waiting(size);
    std::vector<PartisanOutcome> outcome(size);
    for (int position = size - 1; position >= 0; --position) {
        const int vertex = order[position];
        for (int next : left_moves[vertex]) {
            if (left_wins_waiting[next]) left_wins_moving[vertex] = true;
        }
        left_wins_waiting[vertex] = true;
        for (int next : right_moves[vertex]) {
            if (!left_wins_moving[next]) left_wins_waiting[vertex] = false;
        }

        if (left_wins_moving[vertex] && left_wins_waiting[vertex]) {
            outcome[vertex] = PartisanOutcome::Left;
        } else if (!left_wins_moving[vertex] && !left_wins_waiting[vertex]) {
            outcome[vertex] = PartisanOutcome::Right;
        } else if (left_wins_moving[vertex]) {
            outcome[vertex] = PartisanOutcome::Next;
        } else {
            outcome[vertex] = PartisanOutcome::Previous;
        }
    }
    return outcome;
}

}  // namespace game
}  // namespace m1une


#line 1 "game/retrograde_analysis.hpp"



#line 8 "game/retrograde_analysis.hpp"

namespace m1une {
namespace game {

enum class GameOutcome { Win, Lose, Draw };

struct RetrogradeResult {
    std::vector<GameOutcome> outcome;
    std::vector<int> distance;
    std::vector<int> move;
};

// graph[v] contains the states reachable from v in one move.
inline RetrogradeResult retrograde_analysis(
    const std::vector<std::vector<int>>& graph
) {
    const int size = int(graph.size());
    std::vector<std::vector<int>> reverse_graph(size);
    std::vector<int> remaining(size);
    for (int vertex = 0; vertex < size; ++vertex) {
        remaining[vertex] = int(graph[vertex].size());
        for (int next : graph[vertex]) {
            assert(0 <= next && next < size);
            reverse_graph[next].push_back(vertex);
        }
    }

    std::vector<GameOutcome> outcome(size, GameOutcome::Draw);
    std::vector<int> distance(size, -1);
    std::vector<int> move(size, -1);
    std::vector<int> longest_win_successor(size);
    std::vector<int> longest_win_move(size, -1);
    std::vector<bool> decided(size);
    std::queue<int> queue;
    for (int vertex = 0; vertex < size; ++vertex) {
        if (remaining[vertex] == 0) {
            outcome[vertex] = GameOutcome::Lose;
            distance[vertex] = 0;
            decided[vertex] = true;
            queue.push(vertex);
        }
    }

    while (!queue.empty()) {
        const int vertex = queue.front();
        queue.pop();
        for (int previous : reverse_graph[vertex]) {
            if (decided[previous]) continue;
            if (outcome[vertex] == GameOutcome::Lose) {
                outcome[previous] = GameOutcome::Win;
                distance[previous] = distance[vertex] + 1;
                move[previous] = vertex;
                decided[previous] = true;
                queue.push(previous);
            } else {
                if (longest_win_move[previous] == -1
                    || longest_win_successor[previous] < distance[vertex]) {
                    longest_win_successor[previous] = distance[vertex];
                    longest_win_move[previous] = vertex;
                }
                if (--remaining[previous] == 0) {
                    outcome[previous] = GameOutcome::Lose;
                    distance[previous] = longest_win_successor[previous] + 1;
                    move[previous] = longest_win_move[previous];
                    decided[previous] = true;
                    queue.push(previous);
                }
            }
        }
    }
    for (int vertex = 0; vertex < size; ++vertex) {
        if (outcome[vertex] != GameOutcome::Draw) continue;
        for (int next : graph[vertex]) {
            if (outcome[next] == GameOutcome::Draw) {
                move[vertex] = next;
                break;
            }
        }
    }
    return {std::move(outcome), std::move(distance), std::move(move)};
}

}  // namespace game
}  // namespace m1une


#line 1 "game/silver_dollar_game.hpp"



#line 7 "game/silver_dollar_game.hpp"

namespace m1une {
namespace game {

template <typename T>
T silver_dollar_grundy(const std::vector<T>& coins) {
    for (int index = 0; index < int(coins.size()); ++index) {
        if constexpr (std::is_signed_v<T>) assert(coins[index] >= 0);
        if (index != 0) assert(coins[index - 1] < coins[index]);
    }

    T result{};
    int index = int(coins.size()) % 2;
    if (index == 1) result ^= coins[0];
    for (; index + 1 < int(coins.size()); index += 2) {
        result ^= coins[index + 1] - coins[index] - 1;
    }
    return result;
}

template <typename T>
bool silver_dollar_first_player_wins(const std::vector<T>& coins) {
    return silver_dollar_grundy(coins) != 0;
}

}  // namespace game
}  // namespace m1une


#line 1 "game/subtraction_game.hpp"



#include <algorithm>
#line 7 "game/subtraction_game.hpp"

namespace m1une {
namespace game {

inline std::vector<int> subtraction_game_grundy(
    int max_heap,
    const std::vector<int>& moves
) {
    assert(max_heap >= 0);
    for (int move : moves) assert(move > 0);

    std::vector<int> grundy(max_heap + 1);
    std::vector<int> seen(moves.size() + 1, -1);
    for (int heap = 1; heap <= max_heap; ++heap) {
        for (int move : moves) {
            if (move > heap) continue;
            const int value = grundy[heap - move];
            if (value < int(seen.size())) seen[value] = heap;
        }
        while (
            grundy[heap] < int(seen.size())
            && seen[grundy[heap]] == heap
        ) {
            grundy[heap]++;
        }
    }
    return grundy;
}

inline int subtraction_game_nim_sum(
    const std::vector<int>& heaps,
    const std::vector<int>& moves
) {
    int max_heap = 0;
    for (int heap : heaps) {
        assert(heap >= 0);
        max_heap = std::max(max_heap, heap);
    }
    const std::vector<int> grundy = subtraction_game_grundy(max_heap, moves);
    int result = 0;
    for (int heap : heaps) result ^= grundy[heap];
    return result;
}

inline bool subtraction_game_first_player_wins(
    const std::vector<int>& heaps,
    const std::vector<int>& moves
) {
    return subtraction_game_nim_sum(heaps, moves) != 0;
}

}  // namespace game
}  // namespace m1une


#line 13 "game/all.hpp"


#line 4 "verify/game/game_algorithms.test.cpp"

#line 1 "utilities/fast_io.hpp"



#line 6 "utilities/fast_io.hpp"
#include <cerrno>
#include <charconv>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#line 12 "utilities/fast_io.hpp"
#include <cstring>
#line 14 "utilities/fast_io.hpp"
#include <string>
#include <sys/stat.h>
#line 18 "utilities/fast_io.hpp"
#include <unistd.h>
#line 20 "utilities/fast_io.hpp"

namespace m1une {
namespace utilities {

struct FastOutput;

namespace internal {

// Shared with the convenience helpers in template.hpp.
inline FastOutput* standard_output_instance = nullptr;

// Detect std::begin(x), std::end(x).
template <class T, class = void>
struct is_range : std::false_type {};

template <class T>
struct is_range<T, std::void_t<
    decltype(std::begin(std::declval<T&>())),
    decltype(std::end(std::declval<T&>()))
>> : std::true_type {};

template <class T>
inline constexpr bool is_range_v = is_range<T>::value;

template <class T>
using range_reference_t = decltype(*std::begin(std::declval<T&>()));

template <class T>
using range_value_t = std::remove_cv_t<std::remove_reference_t<range_reference_t<T>>>;

template <class T, class = void>
struct range_stored_value {
    using type = range_value_t<T>;
};

template <class T>
struct range_stored_value<T, std::void_t<typename std::remove_cv_t<std::remove_reference_t<T>>::value_type>> {
    using type = typename std::remove_cv_t<std::remove_reference_t<T>>::value_type;
};

template <class T>
using range_stored_value_t = typename range_stored_value<T>::type;

// Treat strings and C strings as scalar output objects, not as ranges.
template <class T>
struct is_char_array : std::false_type {};

template <class T, std::size_t N>
struct is_char_array<T[N]>
    : std::bool_constant<std::is_same_v<std::remove_cv_t<T>, char>> {};

template <class T>
struct is_string_like
    : std::bool_constant<
          std::is_same_v<std::decay_t<T>, std::string>
          || std::is_same_v<std::decay_t<T>, const char*>
          || std::is_same_v<std::decay_t<T>, char*>
          || is_char_array<std::remove_reference_t<T>>::value
      > {};

template <class T>
inline constexpr bool is_string_like_v = is_string_like<T>::value;

// ModInt-like type: x.val() is printable, and x can be assigned from long long.
template <class T, class = void>
struct has_val_method : std::false_type {};

template <class T>
struct has_val_method<T, std::void_t<decltype(std::declval<const T&>().val())>>
    : std::true_type {};

template <class T>
inline constexpr bool has_val_method_v = has_val_method<T>::value;

template <class T, class = void>
struct has_static_mod_raw : std::false_type {};

template <class T>
struct has_static_mod_raw<
    T, std::void_t<decltype(T::mod()), decltype(T::raw(std::declval<uint32_t>()))>>
    : std::true_type {};

template <class T>
inline constexpr bool has_static_mod_raw_v = has_static_mod_raw<T>::value;

// libstdc++ before GCC 16 does not classify __int128 as an integral type in
// strict ISO modes such as -std=c++23. Keep the fast-I/O interface independent
// of that implementation detail.
template <class T>
inline constexpr bool is_integral_v =
    std::is_integral_v<T>
    || std::is_same_v<std::remove_cv_t<T>, __int128_t>
    || std::is_same_v<std::remove_cv_t<T>, __uint128_t>;

template <class T>
inline constexpr bool is_signed_v =
    std::is_signed_v<T>
    || std::is_same_v<std::remove_cv_t<T>, __int128_t>;

template <class T>
struct make_unsigned {
    using type = std::make_unsigned_t<T>;
};

template <>
struct make_unsigned<__int128_t> {
    using type = __uint128_t;
};

template <>
struct make_unsigned<__uint128_t> {
    using type = __uint128_t;
};

template <class T>
using make_unsigned_t = typename make_unsigned<std::remove_cv_t<T>>::type;

}  // namespace internal

struct FastInput {
    static constexpr int buffer_size = 1 << 20;

   private:
    std::FILE* _stream;
    char _buffer[buffer_size];
    int _position;
    int _length;
    int _file_descriptor;
    bool _streaming;

    bool refill() {
        _position = 0;
        if (_streaming) {
            ssize_t length;
            do {
                length = ::read(_file_descriptor, _buffer, buffer_size);
            } while (length < 0 && errno == EINTR);
            if (length <= 0) {
                _length = 0;
                return false;
            }
            _length = int(length);
        } else {
            _length = int(std::fread(_buffer, 1, buffer_size, _stream));
        }
        return _length != 0;
    }

    template <class T>
    bool read_integer_from_stream(T& value) {
        if (!skip_spaces()) return false;
        int c = read_char_raw();

        bool negative = false;
        if (c == '-') {
            negative = true;
            c = read_char_raw();
        }

        if constexpr (internal::is_signed_v<T>) {
            T result = 0;
            while ('0' <= c && c <= '9') {
                result = negative ? result * 10 - (c - '0')
                                  : result * 10 + (c - '0');
                c = read_char_raw();
            }
            value = result;
        } else {
            T result = 0;
            while ('0' <= c && c <= '9') {
                result = result * 10 + T(c - '0');
                c = read_char_raw();
            }
            value = negative ? T(0) - result : result;
        }
        return true;
    }

    bool prepare_number() {
        if (_length - _position >= 64) return true;
        const int remaining = _length - _position;
        if (remaining > 0) std::memmove(_buffer, _buffer + _position, remaining);
        const int added = int(std::fread(_buffer + remaining, 1, buffer_size - remaining, _stream));
        _position = 0;
        _length = remaining + added;
        if (_length < buffer_size) _buffer[_length] = '\0';
        return _length != 0;
    }

   public:
    explicit FastInput(std::FILE* stream = stdin)
        : _stream(stream),
          _position(0),
          _length(0),
          _file_descriptor(::fileno(stream)),
          _streaming([&] {
              struct stat status;
              return _file_descriptor >= 0
                     && ::fstat(_file_descriptor, &status) == 0
                     && !S_ISREG(status.st_mode);
          }()) {}

    FastInput(const FastInput&) = delete;
    FastInput& operator=(const FastInput&) = delete;

    int read_char_raw() {
        if (_position == _length && !refill()) return EOF;
        return _buffer[_position++];
    }

    bool skip_spaces() {
        int c = read_char_raw();
        while (c != EOF && c <= ' ') c = read_char_raw();
        if (c == EOF) return false;
        --_position;
        return true;
    }

    bool read(char& value) {
        if (!skip_spaces()) return false;
        value = char(read_char_raw());
        return true;
    }

    bool read(std::string& value) {
        if (!skip_spaces()) return false;
        value.clear();
        while (true) {
            const int begin = _position;
            while (_position < _length &&
                   static_cast<unsigned char>(_buffer[_position]) > ' ') {
                ++_position;
            }
            value.append(_buffer + begin, _position - begin);
            if (_position < _length) {
                ++_position;
                return true;
            }
            if (!refill()) return true;
        }
    }

    bool read(bool& value) {
        int x;
        if (!read(x)) return false;
        value = x != 0;
        return true;
    }

    template <class T>
    std::enable_if_t<
        internal::is_integral_v<T>
            && !std::is_same_v<std::remove_cv_t<T>, bool>
            && !std::is_same_v<std::remove_cv_t<T>, char>,
        bool
    >
    read(T& value) {
        if (_streaming) return read_integer_from_stream(value);
        if (!prepare_number()) return false;
        int c = static_cast<unsigned char>(_buffer[_position++]);
        while (c <= ' ') c = static_cast<unsigned char>(_buffer[_position++]);

        bool negative = false;
        if (c == '-') {
            negative = true;
            c = static_cast<unsigned char>(_buffer[_position++]);
        }

        if constexpr (internal::is_signed_v<T>) {
            T result = 0;
            while ('0' <= c && c <= '9') {
                const int first = c - '0';
                const int second = static_cast<unsigned char>(_buffer[_position]) - '0';
                if (0 <= second && second <= 9) {
                    result = negative ? result * 100 - (first * 10 + second)
                                      : result * 100 + (first * 10 + second);
                    ++_position;
                } else {
                    result = negative ? result * 10 - first : result * 10 + first;
                }
                c = static_cast<unsigned char>(_buffer[_position++]);
            }
            value = result;
        } else {
            T result = 0;
            while ('0' <= c && c <= '9') {
                const unsigned first = unsigned(c - '0');
                const int second = static_cast<unsigned char>(_buffer[_position]) - '0';
                if (0 <= second && second <= 9) {
                    result = result * 100 + T(first * 10 + unsigned(second));
                    ++_position;
                } else {
                    result = result * 10 + T(first);
                }
                c = static_cast<unsigned char>(_buffer[_position++]);
            }
            value = negative ? T(0) - result : result;
        }
        if (_position > _length) _position = _length;
        return true;
    }

    template <class T>
    std::enable_if_t<std::is_floating_point_v<T>, bool>
    read(T& value) {
        if (!skip_spaces()) return false;
        int c = read_char_raw();
        bool negative = false;
        if (c == '-' || c == '+') {
            negative = c == '-';
            c = read_char_raw();
        }

        long double result = 0;
        while ('0' <= c && c <= '9') {
            result = result * 10 + (c - '0');
            c = read_char_raw();
        }
        if (c == '.') {
            long double place = 0.1L;
            c = read_char_raw();
            while ('0' <= c && c <= '9') {
                result += (c - '0') * place;
                place *= 0.1L;
                c = read_char_raw();
            }
        }
        if (c == 'e' || c == 'E') {
            c = read_char_raw();
            bool exponent_negative = false;
            if (c == '-' || c == '+') {
                exponent_negative = c == '-';
                c = read_char_raw();
            }
            int exponent = 0;
            while ('0' <= c && c <= '9') {
                exponent = exponent * 10 + (c - '0');
                c = read_char_raw();
            }
            long double scale = 1;
            long double power = 10;
            while (exponent > 0) {
                if (exponent & 1) scale *= power;
                power *= power;
                exponent >>= 1;
            }
            result = exponent_negative ? result / scale : result * scale;
        }
        value = static_cast<T>(negative ? -result : result);
        return true;
    }

    template <class T>
    std::enable_if_t<
        internal::has_val_method_v<T>
            && !internal::is_integral_v<T>
            && !internal::is_range_v<T>,
        bool
    >
    read(T& value) {
        long long x;
        if (!read(x)) return false;
        if constexpr (internal::has_static_mod_raw_v<T>) {
            if (x >= 0 && uint64_t(x) < uint64_t(T::mod())) {
                value = T::raw(uint32_t(x));
            } else {
                value = T(x);
            }
        } else {
            value = T(x);
        }
        return true;
    }

    template <class First, class Second>
    bool read(std::pair<First, Second>& value) {
        if (!read(value.first)) return false;
        return read(value.second);
    }

    template <class Range>
    std::enable_if_t<
        internal::is_range_v<Range>
            && !internal::is_string_like_v<Range>,
        bool
    >
    read(Range& range) {
        using StoredValue = internal::range_stored_value_t<Range>;
        constexpr bool nested = internal::is_range_v<StoredValue>
                                && !internal::is_string_like_v<StoredValue>;

        for (auto&& value : range) {
            if constexpr (std::is_same_v<StoredValue, bool> && !nested) {
                bool x;
                if (!read(x)) return false;
                value = x;
            } else {
                if (!read(value)) return false;
            }
        }
        return true;
    }

    template <class First, class Second, class... Rest>
    bool read(First& first, Second& second, Rest&... rest) {
        if (!read(first)) return false;
        return read(second, rest...);
    }

    template <class T>
    FastInput& operator>>(T& value) {
        if (!read(value)) std::abort();
        return *this;
    }
};

struct FastOutput {
    static constexpr int buffer_size = 1 << 20;

   private:
    inline static const auto digit_quads = [] {
        std::array<char, 40000> result{};
        for (int i = 0; i < 10000; i++) {
            int value = i;
            for (int j = 3; j >= 0; j--) {
                result[4 * i + j] = char('0' + value % 10);
                value /= 10;
            }
        }
        return result;
    }();

    std::FILE* _stream;
    char _buffer[buffer_size];
    int _position;
    int _precision;
    std::chars_format _float_format;
    char _range_separator;
    std::string* _capture = nullptr;

    template <class T>
    std::string format_cell(const T& value) {
        std::string result;
        struct CaptureGuard {
            std::string*& target;
            std::string* previous;
            ~CaptureGuard() { target = previous; }
        } guard{_capture, _capture};
        _capture = &result;
        write(value);
        return result;
    }

    template <class Matrix>
    void write_aligned_matrix(const Matrix& matrix) {
        std::vector<std::vector<std::string>> rows;
        std::vector<std::size_t> widths;
        for (const auto& row : matrix) {
            auto& cells = rows.emplace_back();
            std::size_t column = 0;
            for (const auto& value : row) {
                cells.push_back(format_cell(value));
                if (column == widths.size()) widths.push_back(0);
                widths[column] = std::max(widths[column], cells.back().size());
                ++column;
            }
        }
        bool first = true;
        for (const auto& row : rows) {
            if (!first) write_char('\n');
            first = false;
            for (std::size_t column = 0; column < row.size(); ++column) {
                if (column != 0) write_char(_range_separator);
                for (std::size_t padding = row[column].size();
                     padding < widths[column]; ++padding) {
                    write_char(' ');
                }
                write(row[column]);
            }
        }
    }

   public:
    explicit FastOutput(std::FILE* stream = stdout)
        : _stream(stream),
          _position(0),
          _precision(6),
          _float_format(std::chars_format::general),
          _range_separator(' ') {
        if (_stream == stdout
            && internal::standard_output_instance == nullptr) {
            internal::standard_output_instance = this;
        }
    }

    FastOutput(const FastOutput&) = delete;
    FastOutput& operator=(const FastOutput&) = delete;

    ~FastOutput() {
        flush();
        if (internal::standard_output_instance == this) {
            internal::standard_output_instance = nullptr;
        }
    }

    void flush() {
        if (_position != 0) {
            std::fwrite(_buffer, 1, _position, _stream);
            _position = 0;
        }
        std::fflush(_stream);
    }

    void write_char(char c) {
        if (_capture != nullptr) {
            _capture->push_back(c);
            return;
        }
        if (_position == buffer_size) flush();
        _buffer[_position++] = c;
    }

    void write(const char* s) {
        while (*s != '\0') write_char(*s++);
    }

    void write(const std::string& s) {
        if (_capture != nullptr) {
            _capture->append(s);
            return;
        }
        std::size_t position = 0;
        while (position < s.size()) {
            if (_position == buffer_size) flush();
            const std::size_t copied =
                std::min<std::size_t>(buffer_size - _position, s.size() - position);
            std::memcpy(_buffer + _position, s.data() + position, copied);
            _position += int(copied);
            position += copied;
        }
    }

    void write(char c) {
        write_char(c);
    }

    void write(bool value) {
        write_char(value ? '1' : '0');
    }

    template <class T>
    std::enable_if_t<std::is_floating_point_v<T>>
    write(T value) {
        char digits[128];
        auto [end, error] = std::to_chars(
            digits,
            digits + sizeof(digits),
            value,
            _float_format,
            _precision
        );
        if (error != std::errc()) std::abort();
        for (const char* pointer = digits; pointer != end; pointer++) {
            write_char(*pointer);
        }
    }

    template <class T>
    std::enable_if_t<
        internal::is_integral_v<T>
            && !std::is_same_v<std::remove_cv_t<T>, bool>
            && !std::is_same_v<std::remove_cv_t<T>, char>
    >
    write(T value) {
        using Raw = std::remove_cv_t<T>;
        using Unsigned = internal::make_unsigned_t<Raw>;

        Unsigned magnitude;
        if constexpr (internal::is_signed_v<Raw>) {
            if (value < 0) {
                write_char('-');
                magnitude = Unsigned(0) - Unsigned(value);
            } else {
                magnitude = Unsigned(value);
            }
        } else {
            magnitude = value;
        }

        if (magnitude == 0) {
            write_char('0');
            return;
        }

        unsigned chunks[16];
        int count = 0;
        while (magnitude >= 10000) {
            const Unsigned quotient = magnitude / 10000;
            chunks[count++] = unsigned(magnitude - quotient * 10000);
            magnitude = quotient;
        }
        if (_capture == nullptr && _position > buffer_size - 64) flush();
        char captured[64];
        char* const begin = _capture != nullptr ? captured : _buffer + _position;
        char* destination = begin;
        const unsigned leading = unsigned(magnitude);
        const char* first = digit_quads.data() + 4 * leading;
        int skip = leading < 10 ? 3 : leading < 100 ? 2 : leading < 1000 ? 1 : 0;
        for (; skip < 4; skip++) *destination++ = first[skip];
        while (count--) {
            const char* digits = digit_quads.data() + 4 * chunks[count];
            std::memcpy(destination, digits, 4);
            destination += 4;
        }
        if (_capture != nullptr) {
            _capture->append(begin, destination - begin);
        } else {
            _position += int(destination - begin);
        }
    }

    template <class T>
    std::enable_if_t<
        internal::has_val_method_v<T>
            && !internal::is_integral_v<T>
            && !internal::is_range_v<T>
    >
    write(const T& value) {
        write(value.val());
    }

    template <class First, class Second>
    void write(const std::pair<First, Second>& value) {
        write(value.first);
        write_char(' ');
        write(value.second);
    }

    template <class Range>
    std::enable_if_t<
        internal::is_range_v<Range>
            && !internal::is_string_like_v<Range>
    >
    write(const Range& range) {
        using StoredValue = internal::range_stored_value_t<const Range>;
        constexpr bool nested = internal::is_range_v<StoredValue>
                                && !internal::is_string_like_v<StoredValue>;

        bool first = true;
        for (const auto& value : range) {
            if (!first) write_char(nested ? '\n' : _range_separator);
            first = false;
            if constexpr (std::is_same_v<StoredValue, bool> && !nested) {
                write(static_cast<bool>(value));
            } else {
                write(value);
            }
        }
    }

    template <class First, class... Rest>
    void print(const First& first, const Rest&... rest) {
        write(first);
        ((write_char(' '), write(rest)), ...);
    }

    void println() {
        write_char('\n');
    }

    void set_precision(int precision) {
        _precision = precision;
    }

    void set_fixed(int precision = 6) {
        _float_format = std::chars_format::fixed;
        _precision = precision;
    }

    void set_general(int precision = 6) {
        _float_format = std::chars_format::general;
        _precision = precision;
    }

    void set_range_separator(char separator) {
        _range_separator = separator;
    }

    template <class Matrix>
    void write_aligned(const Matrix& matrix) {
        using Row = internal::range_stored_value_t<const Matrix>;
        using Cell = internal::range_stored_value_t<const Row>;
        static_assert(internal::is_range_v<Row> && !internal::is_string_like_v<Row>,
                      "write_aligned requires a two-dimensional range");
        static_assert(!internal::is_range_v<Cell> || internal::is_string_like_v<Cell>,
                      "write_aligned requires scalar cells");
        write_aligned_matrix(matrix);
    }

    template <class Matrix>
    void println_aligned(const Matrix& matrix) {
        write_aligned(matrix);
        write_char('\n');
    }

    template <class... Args>
    void println(const Args&... args) {
        print(args...);
        write_char('\n');
    }

    template <class T>
    FastOutput& operator<<(const T& value) {
        write(value);
        return *this;
    }
};

}  // namespace utilities
}  // namespace m1une


#line 9 "verify/game/game_algorithms.test.cpp"
#include <random>
#line 11 "verify/game/game_algorithms.test.cpp"

namespace {

using m1une::game::GameOutcome;

void test_nim() {
    std::vector<int> empty;
    assert(m1une::game::nim_sum(empty) == 0);
    assert(!m1une::game::nim_first_player_wins(empty));
    assert(m1une::game::misere_nim_first_player_wins(empty));

    std::vector<int> ordinary = {1, 4, 5};
    assert(m1une::game::nim_sum(ordinary) == 0);
    assert(!m1une::game::nim_first_player_wins(ordinary));

    std::vector<int> one_one = {1, 1};
    std::vector<int> one_one_one = {1, 1, 1};
    assert(m1une::game::misere_nim_first_player_wins(one_one));
    assert(!m1une::game::misere_nim_first_player_wins(one_one_one));

    std::vector<int> general = {1, 2, 3};
    assert(!m1une::game::misere_nim_first_player_wins(general));

    for (int code = 0; code < 625; ++code) {
        int remaining = code;
        std::vector<int> heaps(4);
        for (int& heap : heaps) {
            heap = remaining % 5;
            remaining /= 5;
        }

        auto ordinary_move = m1une::game::nim_winning_move(heaps);
        assert(bool(ordinary_move) == m1une::game::nim_first_player_wins(heaps));
        if (ordinary_move) {
            assert(0 <= ordinary_move->heap && ordinary_move->heap < 4);
            assert(ordinary_move->new_size < heaps[ordinary_move->heap]);
            heaps[ordinary_move->heap] = ordinary_move->new_size;
            assert(!m1une::game::nim_first_player_wins(heaps));
        }

        remaining = code;
        for (int& heap : heaps) {
            heap = remaining % 5;
            remaining /= 5;
        }
        const bool has_stone = std::any_of(
            heaps.begin(),
            heaps.end(),
            [](int heap) { return heap != 0; }
        );
        auto misere_move = m1une::game::misere_nim_winning_move(heaps);
        assert(
            bool(misere_move)
            == (has_stone && m1une::game::misere_nim_first_player_wins(heaps))
        );
        if (misere_move) {
            assert(0 <= misere_move->heap && misere_move->heap < 4);
            assert(misere_move->new_size < heaps[misere_move->heap]);
            heaps[misere_move->heap] = misere_move->new_size;
            assert(!m1une::game::misere_nim_first_player_wins(heaps));
        }
    }
}

std::vector<int> naive_grundy(const std::vector<std::vector<int>>& graph) {
    const int size = int(graph.size());
    std::vector<int> result(size);
    for (int vertex = size - 1; vertex >= 0; --vertex) {
        std::vector<bool> appears(size + 1);
        for (int next : graph[vertex]) appears[result[next]] = true;
        while (appears[result[vertex]]) result[vertex]++;
    }
    return result;
}

void test_grundy_random() {
    std::mt19937 random(123456789);
    for (int size = 0; size <= 40; ++size) {
        for (int trial = 0; trial < 100; ++trial) {
            std::vector<std::vector<int>> graph(size);
            for (int from = 0; from < size; ++from) {
                for (int to = from + 1; to < size; ++to) {
                    if (random() % 5 == 0) graph[from].push_back(to);
                }
            }
            assert(m1une::game::grundy_numbers(graph) == naive_grundy(graph));
        }
    }
}

std::vector<GameOutcome> naive_outcomes(
    const std::vector<std::vector<int>>& graph
) {
    const int size = int(graph.size());
    std::vector<GameOutcome> result(size, GameOutcome::Draw);
    std::vector<bool> decided(size);
    for (int vertex = 0; vertex < size; ++vertex) {
        if (graph[vertex].empty()) {
            result[vertex] = GameOutcome::Lose;
            decided[vertex] = true;
        }
    }

    bool changed = true;
    while (changed) {
        changed = false;
        for (int vertex = 0; vertex < size; ++vertex) {
            if (decided[vertex]) continue;
            bool has_losing_move = false;
            bool all_moves_win = true;
            for (int next : graph[vertex]) {
                has_losing_move |= decided[next] && result[next] == GameOutcome::Lose;
                all_moves_win &= decided[next] && result[next] == GameOutcome::Win;
            }
            if (has_losing_move || all_moves_win) {
                result[vertex] = has_losing_move ? GameOutcome::Win : GameOutcome::Lose;
                decided[vertex] = true;
                changed = true;
            }
        }
    }
    return result;
}

void test_retrograde_random() {
    std::mt19937 random(987654321);
    for (int size = 0; size <= 30; ++size) {
        for (int trial = 0; trial < 100; ++trial) {
            std::vector<std::vector<int>> graph(size);
            for (int from = 0; from < size; ++from) {
                for (int to = 0; to < size; ++to) {
                    if (random() % 8 == 0) graph[from].push_back(to);
                }
            }
            auto actual = m1une::game::retrograde_analysis(graph);
            assert(actual.outcome == naive_outcomes(graph));
            for (int vertex = 0; vertex < size; ++vertex) {
                assert((actual.distance[vertex] == -1)
                       == (actual.outcome[vertex] == GameOutcome::Draw));
                if (actual.outcome[vertex] == GameOutcome::Draw) {
                    assert(actual.move[vertex] != -1);
                    assert(actual.outcome[actual.move[vertex]] == GameOutcome::Draw);
                } else if (graph[vertex].empty()) {
                    assert(actual.outcome[vertex] == GameOutcome::Lose);
                    assert(actual.distance[vertex] == 0);
                    assert(actual.move[vertex] == -1);
                } else {
                    assert(
                        std::find(
                            graph[vertex].begin(),
                            graph[vertex].end(),
                            actual.move[vertex]
                        ) != graph[vertex].end()
                    );
                    if (actual.outcome[vertex] == GameOutcome::Win) {
                        assert(
                            actual.outcome[actual.move[vertex]]
                            == GameOutcome::Lose
                        );
                        int best = size + 1;
                        for (int next : graph[vertex]) {
                            if (actual.outcome[next] == GameOutcome::Lose) {
                                best = std::min(best, actual.distance[next] + 1);
                            }
                        }
                        assert(actual.distance[vertex] == best);
                    } else {
                        assert(
                            actual.outcome[actual.move[vertex]]
                            == GameOutcome::Win
                        );
                        int best = 0;
                        for (int next : graph[vertex]) {
                            best = std::max(best, actual.distance[next] + 1);
                        }
                        assert(actual.distance[vertex] == best);
                    }
                    assert(
                        actual.distance[vertex]
                        == actual.distance[actual.move[vertex]] + 1
                    );
                }
            }
        }
    }

    std::vector<std::vector<int>> chain(5);
    chain[0].push_back(1);
    chain[1].push_back(2);
    chain[2].push_back(3);
    chain[3].push_back(4);
    auto result = m1une::game::retrograde_analysis(chain);
    for (int vertex = 0; vertex < 5; ++vertex) {
        assert(result.distance[vertex] == 4 - vertex);
    }
}

}  // namespace

int main() {
    m1une::utilities::FastInput fast_input;
    m1une::utilities::FastOutput fast_output;

    test_nim();
    test_grundy_random();
    test_retrograde_random();

    long long first, second;
    fast_input >> first >> second;
    fast_output << first + second << '\n';
}
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