#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<bitset>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<deque>
#include<list>
#include<iomanip>
#include<cmath>
#include<cstring>
#include<functional>
#include<cstdio>
#include<cstdlib>
#include<unordered_map>
#include<unordered_set>
using namespace std;

#define repr(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define rep(i, n) repr(i, 0, n)
#define INF 2e9
#define MOD 1000000007
//#define MOD 998244353
#define LINF (long long)4e18
#define jck 3.141592

const double EPS = 1e-10;

using ll = long long;
using Pi = pair<int,int>;
using Pl = pair<ll,ll>;



int main(){
    int N; cin >> N;
    set<string> st;
    vector<string> a(N),b(N);
    map<string,bool> mp;
    rep(i,N){
        cin >> a[i] >> b[i];
        st.insert(b[i]);
        mp[b[i]] = false;
    }
    rep(i,N) st.erase(a[i]);
    rep(i,N){
        if(st.find(b[i]) != st.end()){
            if(!mp[b[i]]){
                mp[b[i]] = true;
                cout << b[i] << endl;
            }
        }
    }
    

}