#include <bits/stdc++.h>
using namespace std;

#define pub push_back
#define el '\n'

const int mxn = 1e5+5;

int n;
string a[mxn];

void solve() {
    cin >> n;

    for(int i = 1; i <= n; i++) cin >> a[i];

    string tmp;
    for(int i = 1; i <= n; i++) {
        cin >> tmp;

        if (tmp == a[i]) continue;

        cout << a[i];
        break;
    }
}

signed main() {
    cin.tie(0) -> sync_with_stdio(0);

    int t = 1;
    // cin >> t;

    for (int i = 1; i <= t; i++) solve();
}