#include <iostream>
#include <string>
#include <vector>
using namespace std;
int main()
{
	int N;
	cin >> N;
	vector<string> S(N);
	string T;
	for (int i = 0; i < N; i++)
	{
		cin >> S[i];
	}
	for (int i = 0; i < N; i++)
	{
		cin >> T;
		if (S[i] != T)
		{
			N = i+1;
			break;
		}
	}

	cout << N << endl;
	cout << S[N - 1] << endl;
	cout << T << endl;
	return 0;
}