#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define ITER iterator
using namespace std;
typedef long long lint;
typedef pair<int, int> pi;
typedef vector<int> vi;
typedef vector<pi> vpi;
typedef set<int> si;
const int inf = 0x3f3f3f3f;
const int maxn = 0;
const int MOD = 1e9 + 7;
int n;
map<string, int> m;
int main ()
{
ios::sync_with_stdio(NULL);
cin.tie(0); cout.tie(0);
cin >> n;
for(int i = 0; i < n; ++i) {
string ime;
cin >> ime;
++m[ime];
}
for(int i = 0; i < n - 1; ++i) {
string ime;
cin >> ime;
--m[ime];
}
for(map<string, int>::ITER it = m.begin(); it != m.end(); ++it) {
if(it -> S != 0) {
cout << it -> F;
break;
}
}
return 0;
}
