// iostream is too mainstream
#include <cstdio>
// bitch please
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <list>
#include <cmath>
#include <iomanip>
#define dibs reserve
#define OVER9000 1234567890
#define ALL_THE(CAKE,LIE) for(auto LIE =CAKE.begin(); LIE != CAKE.end(); LIE++)
#define tisic 47
#define soclose 1e-8
#define chocolate win
// so much chocolate
#define patkan 9
#define ff first
#define ss second
#define abs(x) ((x < 0)?-(x):x)
#define uint unsigned int
#define dbl long double
using namespace std;
// mylittledoge

int main() {
	cin.sync_with_stdio(0);
	cin.tie(0);
	int N;
	cin >> N;
	long long x =0;
	map<string,int> M;
	for(int i =0; i < N; i++) {
		string s;
		cin >> s;
		if(M.find(s) != M.end()) x +=M[s];
		else {
			int a =M.size();
			x +=a;
			M[s] =a;}
		}

	for(int i =0; i < N-1; i++) {
		string s;
		cin >> s;
		x -=M[s];}

	ALL_THE(M,it) if(x == it->ss) cout << it->ff << "\n";
	return 0;}

// look at my code
// my code is amazing