#include #pragma GCC optimize("Ofast") #define _GLIBCXX_DEBUG using namespace std; using std::cout; using std::cin; using std::endl; using ll=long long; using ld=long double; ll I=1167167167167167167; ll mod=1e9+7; #define rep(i,a) for (ll i=0;i using _pq = priority_queue, greater>; template ll LB(vector &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();} template ll UB(vector &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();} template bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;} template bool chmax(T &a,const T &b){if(a void So(vector &v) {sort(v.begin(),v.end());} template void Sore(vector &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});} void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";} namespace po167{ struct UFtree { std::vector wei; int component; UFtree(int n):par(n),wei(n),component(n){ for(int i=0;i par; }; } using po167::UFtree; //おちこんだりもしたけれど、私はげんきです。 int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int N; cin>>N; UFtree A(N); vector ans(N,-1); vector> G(N); int tmpx=-1,tmpy=-1; map,int> m; vector p; rep(i,N){ int a,b; cin>>a>>b; a--,b--; if(!A.unite(a,b)){ ans[i]=a; p.push_back(a); } else{ m[{a,b}]=i; m[{b,a}]=i; G[a].push_back(b); G[b].push_back(a); } } set s; for(auto x:p){ if(s.count(A.root(x))){ yneos(0); return 0; } s.insert(A.root(x)); queue q; q.push(x); while(!q.empty()){ int a=q.front(); q.pop(); for(auto y:G[a]){ if(ans[m[{a,y}]]==-1){ ans[m[{a,y}]]=y; q.push(y); } } } } yneos(1); rep(i,N) cout<