#include #pragma GCC diagnostic ignored "-Wsign-compare" #pragma GCC diagnostic ignored "-Wsign-conversion" #define NDEBUG #define SHOW(...) static_cast(0) //!===========================================================!// //! dP dP dP !// //! 88 88 88 !// //! 88aaaaa88a .d8888b. .d8888b. .d888b88 .d8888b. 88d888b. !// //! 88 88 88ooood8 88' '88 88' '88 88ooood8 88' '88 !// //! 88 88 88. ... 88. .88 88. .88 88. ... 88 !// //! dP dP '88888P' '88888P8 '88888P8 '88888P' dP !// //!===========================================================!// template T read() { T v; return std::cin >> v, v; } template std::vector readVec(const std::size_t l) { std::vector v(l); for (auto& e : v) { std::cin >> e; } return v; } using ld = long double; using uint = unsigned int; using ll = long long; using ull = unsigned long long; constexpr unsigned int MOD = 1000000007; template constexpr T INF = std::numeric_limits::max() / 4; template constexpr F PI = static_cast(3.1415926535897932385); std::mt19937 mt{std::random_device{}()}; template bool chmin(T& a, const T& b) { return (a > b ? a = b, true : false); } template bool chmax(T& a, const T& b) { return (a < b ? a = b, true : false); } template std::vector Vec(const std::size_t n, T v) { return std::vector(n, v); } template auto Vec(const std::size_t n, Args... args) { return std::vector(n, Vec(args...)); } template constexpr T popCount(const T u) { #ifdef __has_builtin return u == 0 ? T(0) : (T)__builtin_popcountll(u); #else unsigned long long v = static_cast(u); return v = (v & 0x5555555555555555ULL) + (v >> 1 & 0x5555555555555555ULL), v = (v & 0x3333333333333333ULL) + (v >> 2 & 0x3333333333333333ULL), v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0FULL, static_cast(v * 0x0101010101010101ULL >> 56 & 0x7f); #endif } template constexpr T log2p1(const T u) { #ifdef __has_builtin return u == 0 ? T(0) : T(64 - __builtin_clzll(u)); #else unsigned long long v = static_cast(u); return v = static_cast(v), v |= (v >> 1), v |= (v >> 2), v |= (v >> 4), v |= (v >> 8), v |= (v >> 16), v |= (v >> 32), popCount(v); #endif } template constexpr T clog(const T v) { return v == 0 ? T(0) : log2p1(v - 1); } template constexpr T msbp1(const T v) { return log2p1(v); } template constexpr T lsbp1(const T v) { #ifdef __has_builtin return __builtin_ffsll(v); #else return v == 0 ? T(0) : popCount((v & (-v)) - T(1)) + T(1); #endif } template constexpr bool ispow2(const T v) { return popCount(v) == 1; } template constexpr T ceil2(const T v) { return v == 0 ? T(1) : T(1) << log2p1(v - 1); } template constexpr T floor2(const T v) { return v == 0 ? T(0) : T(1) << (log2p1(v) - 1); } //!=================================================!// //! .88888. dP !// //! d8' '88 88 !// //! 88 88d888b. .d8888b. 88d888b. 88d888b. !// //! 88 YP88 88' '88 88' '88 88' '88 88' '88 !// //! Y8. .88 88 88. .88 88. .88 88 88 !// //! '88888' dP '88888P8 88Y888P' dP dP !// //! 88 !// //! dP !// //!=================================================!// struct Graph { Graph(const std::size_t v) : V{v}, edge(v), rev_edge(v) {} void addEdge(const std::size_t from, const std::size_t to, const bool bi = false) { assert(from < V), assert(to < V); edge[from].push_back(to), rev_edge[to].push_back(from); if (bi) { addEdge(to, from, false); } } const std::vector& operator[](const std::size_t i) const { return assert(i < V), edge[i]; } friend std::ostream& operator<<(std::ostream& os, const Graph& g) { os << "[\n"; for (std::size_t i = 0; i < g.V; i++) { for (const std::size_t to : g.edge[i]) { os << i << "->" << to << "\n"; } } return (os << "]\n"); } std::size_t V; std::vector> edge, rev_edge; }; using Tree = Graph; //!=================================================================!// //! d888888P .d88888b dP !// //! 88 88. "' 88 !// //! 88 .d8888b. 88d888b. 'Y88888b. .d8888b. 88d888b. d8888P !// //! 88 88' '88 88' '88 '8b 88' '88 88' '88 88 !// //! 88 88. .88 88. .88 d8' .8P 88. .88 88 88 !// //! dP '88888P' 88Y888P' Y88888P '88888P' dP dP !// //! 88 !// //! dP !// //!=================================================================!// std::pair> TopSort(const Graph& g) { std::vector srt, used(g.V, 0); auto dfs = [&](auto&& self, const std::size_t s) -> bool { if (used[s] == 1) { return false; } else if (used[s] == 0) { used[s] = 1; for (const std::size_t to : g.edge[s]) { if (not self(self, to)) { return false; } } used[s] = 2, srt.push_back(s); } return true; }; for (std::size_t i = 0; i < g.V; i++) { if (not dfs(dfs, i)) { return {false, srt}; } } std::reverse(srt.begin(), srt.end()); return {true, srt}; } int main() { const int N = read(), M = read(); const int MASK = 1 << N; Graph G(N * MASK); auto E = Vec(N, N, 0); for (int i = 0, a, b, c; i < M; i++) { std::cin >> a >> b >> c, a--, b--; chmax(E[a][b], c), chmax(E[b][a], c); } for (int i = 0; i < N; i++) { for (int j = 0; j < N; j++) { if (E[i][j] == 0) { continue; } for (int mask = 0; mask < MASK; mask++) { if ((mask & (1 << i)) == 0) { continue; } if (mask & (1 << j)) { continue; } G.addEdge(i * MASK + mask, j * MASK + mask + (1 << j)); } } } const auto top = TopSort(G); assert(top.first); std::vector L(N * MASK + 1, 0); for (const int v : top.second) { for (const int to : G[v]) { chmax(L[to], L[v] + E[v / MASK][to / MASK]); } } std::cout << *std::max_element(L.begin(), L.end()) << std::endl; return 0; }