#line 1 "main.cpp" /** * @title Template */ #include #include #include #include #include #include #include #include #line 2 "/Users/kodamankod/Desktop/Programming/Library/other/chmin_chmax.cpp" template constexpr bool chmin(T &lhs, const U &rhs) { if (lhs > rhs) { lhs = rhs; return true; } return false; } template constexpr bool chmax(T &lhs, const U &rhs) { if (lhs < rhs) { lhs = rhs; return true; } return false; } /** * @title Chmin/Chmax */ #line 2 "/Users/kodamankod/Desktop/Programming/Library/other/range.cpp" #line 4 "/Users/kodamankod/Desktop/Programming/Library/other/range.cpp" class range { public: class iterator { private: int64_t M_position; public: constexpr iterator(int64_t position) noexcept: M_position(position) { } constexpr void operator ++ () noexcept { ++M_position; } constexpr bool operator != (iterator other) const noexcept { return M_position != other.M_position; } constexpr int64_t operator * () const noexcept { return M_position; } }; class reverse_iterator { private: int64_t M_position; public: constexpr reverse_iterator(int64_t position) noexcept: M_position(position) { } constexpr void operator ++ () noexcept { --M_position; } constexpr bool operator != (reverse_iterator other) const noexcept { return M_position != other.M_position; } constexpr int64_t operator * () const noexcept { return M_position; } }; private: const iterator M_first, M_last; public: constexpr range(int64_t first, int64_t last) noexcept: M_first(first), M_last(std::max(first, last)) { } constexpr iterator begin() const noexcept { return M_first; } constexpr iterator end() const noexcept { return M_last; } constexpr reverse_iterator rbegin() const noexcept { return reverse_iterator(*M_last - 1); } constexpr reverse_iterator rend() const noexcept { return reverse_iterator(*M_first - 1); } }; /** * @title Range */ #line 2 "/Users/kodamankod/Desktop/Programming/Library/other/rev.cpp" #include #include #line 6 "/Users/kodamankod/Desktop/Programming/Library/other/rev.cpp" template class rev_impl { public: using iterator = decltype(std::rbegin(std::declval())); private: const iterator M_begin; const iterator M_end; public: constexpr rev_impl(T &&cont) noexcept: M_begin(std::rbegin(cont)), M_end(std::rend(cont)) { } constexpr iterator begin() const noexcept { return M_begin; } constexpr iterator end() const noexcept { return M_end; } }; template constexpr decltype(auto) rev(T &&cont) { return rev_impl(std::forward(cont)); } /** * @title Reverser */ #line 2 "/Users/kodamankod/Desktop/Programming/Library/other/fix_point.cpp" #line 4 "/Users/kodamankod/Desktop/Programming/Library/other/fix_point.cpp" template struct fix_point_impl: private Func { explicit constexpr fix_point_impl(Func &&func): Func(std::forward(func)) { } template constexpr decltype(auto) operator () (Args &&... args) const { return Func::operator()(*this, std::forward(args)...); } }; template constexpr decltype(auto) fix_point(Func &&func) { return fix_point_impl(std::forward(func)); } /** * @title Lambda Recursion */ #line 19 "main.cpp" using i32 = int32_t; using i64 = int64_t; using u32 = uint32_t; using u64 = uint64_t; constexpr i32 inf32 = (i32(1) << 30) - 1; constexpr i64 inf64 = (i64(1) << 62) - 1; int main() { i32 N, M; std::cin >> N >> M; std::vector> graph(N), revgraph(N); for (auto i: range(0, M)) { i32 u, v; std::cin >> u >> v; --u; --v; graph[u].push_back(v); revgraph[v].push_back(u); } std::vector visited(N); std::stack stack; const auto tag = fix_point([&](auto dfs, const i32 u) -> void { if (visited[u]) { return; } visited[u] = true; for (auto v: graph[u]) { dfs(v); } stack.push(u); }); for (auto i: range(0, N)) { tag(i); } std::fill(visited.begin(), visited.end(), false); std::vector> group; const auto dec = fix_point([&](auto dfs, const i32 u) -> void { if (visited[u]) { return; } visited[u] = true; group.back().push_back(u); for (auto v: revgraph[u]) { dfs(v); } }); while (!stack.empty()) { const auto u = stack.top(); stack.pop(); if (!visited[u]) { group.push_back({ }); dec(u); } } const i32 G = group.size(); std::vector> newgraph(G); std::vector belong(N); for (auto i: range(0, G)) { for (auto x: group[i]) { belong[x] = i; } } for (auto i: range(0, N)) { for (auto v: graph[i]) { newgraph[belong[i]].push_back(belong[v]); } } i64 ans = 0; std::vector max(G); for (auto i: rev(range(0, G))) { for (auto x: group[i]) { chmax(max[i], x); } for (auto j: newgraph[i]) { chmax(max[i], max[j]); } ans += (i64) max[i] * group[i].size(); } std::cout << ans + N << '\n'; return 0; }