/** * author: shu8Cream * created: 03.02.2023 22:26:17 **/ #include using namespace std; #define overload3(a,b,c,d,...) d #define rep1(i,n) for (int i=0; i<(n); i++) #define rep2(i,a,n) for (int i=(a); i<(n); i++) #define rep(...) overload3(__VA_ARGS__, rep2, rep1)(__VA_ARGS__) #define rrep1(i,n) for (int i=(n-1); i>=0; i--) #define rrep2(i,a,n) for (int i=(n-1); i>=(a); i--) #define rrep(...) overload3(__VA_ARGS__, rrep2, rrep1)(__VA_ARGS__) #define all(x) (x).begin(), (x).end() #define rall(x) (x).rbegin(), (x).rend() #define sz(x) int((x).size()) #define pcnt __builtin_popcountll using ll = long long; using P = pair; template using vc = vector; template using vv = vc>; using vi = vc; using vvi = vv; const int INF = 1e9; const ll LINF = 8e18; templateistream& operator>>(istream&i,vc&v){rep(j,sz(v))i>>v[j];return i;} templatestring join(const T&v,const string& d=""){stringstream s;rep(i,sz(v))(i?s<ostream& operator<<(ostream&o,const vc&v){if(sz(v))o<istream& operator>>(istream&i,pair&v){return i>>v.first>>v.second;} templateostream& operator<<(ostream&o,const pair&v){return o< inline bool chmax(T& a, T b) {if(a inline bool chmin(T& a, T b) {if(a>b) { a=b;return true; } return false;} template string to_string(T s); template string to_string(pair p); string to_string(char c) { return string(1, c); } string to_string(string s) { return s; } string to_string(const char s[]) { return string(s); } template string to_string(T v) { if (v.empty()) return "{}"; string ret = "{"; for (auto x : v) ret += to_string(x) + ","; ret.back() = '}'; return ret; } template string to_string(pair p) { return "{" + to_string(p.first) + ":" + to_string(p.second) + "}"; } void debug_out() { cout << endl; } template void debug_out(Head H, Tail... T) { cout << to_string(H) << " "; debug_out(T...); } #ifdef _DEBUG #define debug(...) debug_out(__VA_ARGS__) #else #define debug(...) #endif struct UnionFind{ vector par; UnionFind(){} UnionFind(int n=0): par(n, -1){} int find(int x){ if(par[x] < 0) return x; return par[x] = find(par[x]); } bool merge(int x, int y){ x = find(x); y = find(y); if(x == y) return false; if(par[x] > par[y]) swap(x,y); //マージテク par[x] += par[y]; par[y] = x; return true; } bool same(int x, int y) {return find(x) == find(y);} int size(int x) {return -par[find(x)];} }; int main() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); ll n,m; cin >> n >> m; vvi to(n); UnionFind uf(n); rep(i,m){ int a,b; cin >> a >> b; a--; b--; to[a].push_back(b); to[b].push_back(a); uf.merge(a,b); } set st; set par; rep(i,n)par.insert(uf.find(i)); vi cnt(n); auto dfs = [&](auto dfs, int s, int p=-1)->void{ st.insert(s); for(auto nv:to[s]){ if(nv==p) continue; if(st.count(nv)){ if(sz(st)%2){ cnt[uf.find(nv)]=1; return; } continue; } dfs(dfs,nv,s); } st.erase(s); }; for(auto p : par){ dfs(dfs,p); } cout << (sz(par)==reduce(all(cnt)) ? "Yes" : "No") << endl; }