#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 = 20005;
vector<vector<int>> graph(2*n,vector<int>());
vector<int> visited(2*n,-1);

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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n;
    map<string,int> mp;
    int id = 0;
    rep(i,n){
        string a,b;
        cin >> a >> b;
        if(mp.find(a) == mp.end()){
            mp[a] = id++;
        } 
        if(mp.find(b) == mp.end()){
            mp[b] = id++;
        }
        graph[mp[a]].push_back(mp[b]);
    }

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

    vector<int> idx;
    rep(i,id){
        if(visited[i] == 1){
            idx.push_back(i);
        }
    }


    vector<string> ans;
    for(int i:idx){
        for(auto p:mp){
            if(i == p.second){
                ans.push_back(p.first);
                break;
            }
        }
    }

    for(string s:ans) cout << s << '\n';

    return 0;
}