#include <bits/stdc++.h>
using namespace std;

#define int long long

signed main(){
    int n;
    cin >> n;
    string a[20010], b[20010];
    
    set<string> s;
    for(int i = 0;i < n;i++){
        cin >> a[i] >> b[i];
        s.insert(a[i]);
    }

    set<string> t;

    for(int i = 0;i < n;i++){
        if(s.find(b[i]) == s.end() && t.find(b[i]) == t.end()){
            cout << b[i] << endl; 
            t.insert(b[i]);
        }
    }

    return 0;
}