#include <bits/stdc++.h> using namespace std; typedef long long ll; int main() { int N; cin >> N; string A[N], B[N]; set<string> g; for (int i = 0; i < N; i++) { cin >> A[i] >> B[i]; g.insert(A[i]); } set<string> f; vector<string> p; for (string s : B) { if (g.count(s) == 0 && f.count(s) == 0) { p.push_back(s); f.insert(s); } } for (string s : p) { cout << s << "\n"; } return 0; }