#include<bits/stdc++.h>
using namespace std;
using ll = long long;
ll _i=0;
#define ffn(x) _i=x
#define fora(y,x) for(ll y=_i;x>y;y++)
#define pb push_back
#define pf push_front
#define debu cout << "hello\n"
#define fi first
#define sec second
const ll limit =998244353;
const ll ous=1000005;
void solve(){
ll n;
cin >> n;
map<string , ll> mp;
fora(i,n){
string h;
cin >> h;
mp[h]++;
}
vector<ll> y;
for(auto j:mp){
y.pb(j.sec);
}
ffn(1);
fora(i , n){
string h;
cin >> h;
mp[h]++;
}
string ans;
ll s = 0;
for(auto j:mp){
if(j.sec != 2*y[s]){
ans = j.fi;
}
s++;
}
cout << ans ;
return;
}
int main(){
ios_base::sync_with_stdio(false);cin.tie(NULL);
ll t=1;
//cin >> t;
while(t--){
solve();
}
return 0;
}
