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

int main() {
  int N;
  cin >> N;
  vector<pair<string, string>> V(N);
  set<string> SE;
  for (int i = 0; i < N; i++) {
    string A, B;
    cin >> A >> B;
    SE.insert(A);
    SE.insert(B);
    V.at(i) = {A, B};
  }
  for (auto [a, b] : V) SE.erase(a);
  set<string> NG;
  for (auto [a, b] : V) {
    if (SE.count(b) && !NG.count(b)) {
      cout << b << "\n";
      NG.insert(b);
    }
  }
}