#include "bits/stdc++.h"
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;

using ll = long long;
const ll MOD = 998244353;

int main() {
    int N;
    cin >> N;
    vector<string> A(N), B(N);
    set<string> st1, st2;
    rep(i, N) {
        cin >> A[i] >> B[i];
        st1.insert(A[i]);
    }
    vector<string> ans(0);
    rep(i, N) {
        if (!st1.count(B[i]) && !st2.count(B[i])) {
            ans.push_back(B[i]);
            st2.insert(B[i]);
        }
    }
    rep(i, ans.size()) {
        cout << ans[i] << endl;
    }
}