#include using namespace std; using ll =long long; void solve(){ map M; ll N; cin>>N; vector S(N),T(N); for(int i=0;i>S[i]>>T[i]; M[S[i]]++; M[T[i]]++; } bool OK=1; for(int i=0;i1&&M[T[i]]>1){ cout<<"No\n"; return; } } cout<<"Yes\n"; } int main(){ ios::sync_with_stdio(false); cin.tie(nullptr); int T=1; // cin>>T; while(T--)solve(); }