#include <bits/stdc++.h>
    using namespace std;
    #include <math.h>
    #include <iomanip>
    #include <cstdint>
    #include <string>
    #include <sstream>
    template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
    template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
    #define rep(i,n) for (int i = 0; i < (n); ++i)
    typedef long long ll;
    typedef unsigned long long ull;
    using P=pair<ll,ll>;
    const ll INF=1e18;
    const int mod=998244353;

    struct Unionfind{
      vector<int>d;
      Unionfind(int n):d(n,-1){}
      int root(int x){
        if(d[x]<0){return x;}
        return d[x]=root(d[x]);
      }
      bool unite(int x,int y){
        x=root(x);y=root(y);
        if(x==y){return false;}
        if(d[x]>d[y]){swap(x,y);}
        d[x]+=d[y];
        d[y]=x;
        return true;
      }
      bool same(int x,int y){return root(x)==root(y);}
      int size(int x){return -d[root(x)];}
    };

    void solve(){
        int n;
        cin>>n;
        Unionfind uf(n);
        vector<int>cnt(n);
        vector<int>a(n),b(n);
        
        vector<int>used(n),ans(n);
        rep(i,n){
            cin>>a[i]>>b[i];
            a[i]--;b[i]--;
            uf.unite(a[i],b[i]);
            if(a[i]==b[i]){ans[i]=a[i]; used[a[i]]=1; }
        }
        rep(i,n){cnt[uf.root(a[i])]++;}
        
        rep(i,n){
            if(uf.root(i)==i){
                if(cnt[uf.root(i)]<uf.size(i)){
                    cout<<"No"<<endl;
                    return;
                }
            }
            if(used[a[i]]&&used[b[i]]){continue;}
            if(!used[a[i]]){
                used[a[i]]=1;
                ans[i]=a[i];
            }
            else{
                used[b[i]]=1;
                ans[i]=b[i];
            }
        }
        cout<<"Yes"<<endl;
        rep(i,ans.size()){
            cout<<ans[i]+1<<endl;
        }
    }

    int main(){
        ios_base::sync_with_stdio(false);
        cin.tie(NULL);
        
        solve();  

        return 0;
    }