#include<bits/stdc++.h>
using namespace std;
#define int long long
#define all(x) x.begin(), x.end()
#define ins insert
#define pb push_back
#define F first
#define S second
const int N = 1e6 + 7, M = 5e5 + 7;
const int mod = 1e9 + 7;
void solve(){
int n;
cin>>n;
string a[n + 1];
map<string, int>mp, mp1;
for(int i = 1; i <= n; i++){
cin>>a[i];
mp1[a[i]]++;
}
for(int i = 1; i < n; i++){
string x;
cin>>x;
mp[x]++;
}
for(int i = 1; i <= n; i++){
if(mp[a[i]] != mp1[a[i]]){
cout<<a[i];
return;
}
}
}
signed main(){
ios_base :: sync_with_stdio(false);
cin.tie(nullptr);
int t = 1;
//cin>>t;
for(int i = 1; i <= t; i++){
//cout<<"Case "<<i<<": ";
solve();
}
}
