#pragma GCC optimize("O2") #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define int ll #define INT128_MAX (__int128)(((unsigned __int128) 1 << ((sizeof(__int128) * __CHAR_BIT__) - 1)) - 1) #define INT128_MIN (-INT128_MAX - 1) #define clock chrono::steady_clock::now().time_since_epoch().count() #ifdef DEBUG #define dbg(x) cout << (#x) << " = " << x << '\n' #else #define dbg(x) #endif namespace R = std::ranges; namespace V = std::views; using namespace std; using ll = long long; using ull = unsigned long long; using ldb = long double; using pii = pair; using pll = pair; //#define double ldb template ostream& operator<<(ostream& os, const pair pr) { return os << pr.first << ' ' << pr.second; } template ostream& operator<<(ostream& os, const array &arr) { for(const T &X : arr) os << X << ' '; return os; } template ostream& operator<<(ostream& os, const vector &vec) { for(const T &X : vec) os << X << ' '; return os; } template ostream& operator<<(ostream& os, const set &s) { for(const T &x : s) os << x << ' '; return os; } signed main() { ios::sync_with_stdio(false), cin.tie(NULL); int n, m; cin >> n >> m; vector> g(n); for(int i = 0; i < m; i++) { int u, v; cin >> u >> v; u--, v--; g[u].emplace_back(v); g[v].emplace_back(u); } vector vis(n); bool ok = true; auto dfs = [&](int v, int c, auto self) -> void { vis[v] = c; for(int x : g[v]) { if (vis[x] == c) ok = false; else if (vis[x] == 0) self(x, 3 - c, self); } }; for(int i = 0; i < n; i++) if (!vis[i]) dfs(i, 1, dfs); cout << (ok ? "Yes\n" : "No\n"); return 0; }