#include <bits/stdc++.h>
using namespace std;
#define int long long
#define REP(i,n) for(int i = 0;i < (int)(n);i++)
#define RREP(i,n) for(int i = (int)n-1;i >= 0;i--)
#define FOR(i,s,n) for(int i = s;i < (int)n;i++)
#define RFOR(i,s,n) for(int i = (int)n-1;i >= s;i--)
#define ALL(a) a.begin(),a.end()
#define IN(a, x, b) (a<=x && x<b)
template<class T>inline bool CHMAX(T&a,T b){if(a<b){a = b;return true;}return false;}
template<class T>inline bool CHMIN(T&a,T b){if(a>b){a = b;return true;}return false;}
constexpr long long INF = 1e18;



signed main(){
	int N;
	cin>>N;
	map<string,pair<int,int>>mp;
	vector<string>a(N),b(N);
	REP(i,N){
		cin>>a[i]>>b[i];
		mp[a[i]].first++;
		mp[b[i]].second++;
	}
	set<string>st;
	REP(i,N){
		auto p = mp[b[i]];
		if(p.first)continue;
		if(st.find(b[i])==st.end()){
			cout<<b[i]<<endl;
			st.insert(b[i]);
		}
	}
}