/*
ID: samikgo1
TASK:
LANG: C++
*/
#include <bits/stdc++.h>
using namespace std;
typedef int ll;
typedef pair<ll,ll> pll;
#define all(x) x.begin(),x.end()
#define allr(x) x.rbegin(),x.rend()
#define f first
#define s second
//#define x first
//#define y second
const int INF = INT32_MAX;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
// freopen("haybales.in","r",stdin);
// freopen("haybales.out","w",stdout);
ll n;cin>>n;
multiset<string> names;
for(int i=0;i<n;i++){string s;cin>>s;names.insert(s);}
for(int i=1;i<n;i++){string s;cin>>s;names.erase(names.find(s));}
cout << *names.begin();
}
