#include #include #define pub push_back #define eb emplace_back #define mp make_pair #define fi first #define se second #define rep(i, n) rep2(i, 0, n) #define rep2(i, m, n) for (ll i = m; i < (n); i++) #define per(i, b) per2(i, 0, b) #define per2(i, a, b) for (ll i = int(b) - 1; i >= int(a); i--) #define ALL(c) (c).begin(), (c).end() using namespace std; using namespace atcoder; using ll = long long; using Pll = pair; using mint = modint998244353; using mint2 = modint1000000007; constexpr long long INF = (1LL << 60); constexpr double EPS = 1e-9; constexpr double PI = 3.141592653589; template bool chmax(T& a, const T& b) { if (a < b) { a = b; // aをbで更新 return true; } return false; } template bool chmin(T& a, const T& b) { if (a > b) { a = b; // aをbで更新 return true; } return false; } template T sq(T x) { return x * x; } std::string zfill(int n, const int width) { std::stringstream ss; ss << std::setw(width) << std::setfill('0') << n; return ss.str(); } int main() { ll N, M; cin >> N >> M; dsu uf(2*N); rep(i, M) { ll a, b; cin >> a >> b; a--, b--; uf.merge(a, b + N); uf.merge(a + N, b); } rep(i, N) { if (!uf.same(i, i + N)) { cout << "No" << endl; return 0; } } cout << "Yes" << endl; }