#include <bits/stdc++.h>
#define int long long
using namespace std;
const int MOD = 1000000007;

signed main() {
  int N;
  cin >> N;
  
  set<string> A;
  vector<string> B(N);
  for( int i = 0; i < N; i++ ){
    string a;
    cin >> a >> B.at(i);
    A.insert(a);
  }
  
  vector<string> ans;
  for( int i = 0; i < N; i++ ){
    if( A.count(B.at(i)) ) continue;
    else ans.push_back(B.at(i));
  }
  
  ans.erase(unique(ans.begin(), ans.end()), ans.end());
  for( int i = 0; i < ans.size(); i++ ) cout << ans.at(i) << endl;
}