#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
const int INF = 1e9;
const int MOD = 1000000007;

int n = 40005;
vector<vector<int>> graph(n,vector<int>());
vector<int> visited(n,-1);

void dfs(int i){
    if(graph[i].size() == 0) visited[i] = 1;
    else{
        visited[i] = 0;
        for(int p:graph[i]){
            dfs(p);
        }
    }
}

int main(){
    int n;
    cin >> n;
    map<int ,string> mp1;
    map<string,int> mp2;
    int id = 0;
    rep(i,n){
        string a,b;
        cin >> a >> b;
        if(mp2.count(a) == 0){
            mp2[a] = id;
            mp1[id++] = a;
        }
        if(mp2.count(b) ==0){
            mp2[b] = id;
            mp1[id++] = b;
        }
        graph[mp2[a]].push_back(mp2[b]);
    }

    rep(i,id){
        if(visited[i] != -1) continue;
        dfs(i);
    }

    rep(i,id){
        if(visited[i] == 1){
            cout << mp1[i] << endl;
        }
    }

    return 0;
}