#include <stdio.h>
#include <stdlib.h>
#include<string.h>

int main()
{
	int N;

	scanf("%d", &N);

	char** S;
	S = (char**)malloc(sizeof(char*) * N);

	char** T;
	T = (char**)malloc(sizeof(char*) * N);

	for (int i = 0; i < N; i++)
	{
		char str[21];
		int len;
		scanf("%s%n",&str,&len);
		S[i] = (char*)malloc(sizeof(char) * len);
		if (S[i] == NULL) {
			return -1;
		}
		for (int j = 0; j < len; j++)
		{
			S[i][j] = str[j];
		}
	}

	for (int i = 0; i < N; i++)
	{
		char str[21];
		int len;
		scanf("%s%n", &str, &len);
		T[i] = (char*)malloc(sizeof(char) * len);
		if (T[i] == NULL) {
			return -1;
		}
		for (int j = 0; j < len; j++)
		{
			T[i][j] = str[j];
		}
	}

	for (int i = 0; i < N; i++)
	{
		if (strcmp(S[i], T[i]) != 0)
		{
			printf("%d\n%s\n%s", i, S[i], T[i]);
			return 0;
		}
	}

	return 0;
}