#410_B.cpp

gistfile1.txt

#include <iostream>
#include <cstdio>
#include <stack>
#include <queue>
#include <algorithm>
#include <cstring>
#include <cmath>

#define MAX(a,b) (a)>(b)?(a):(b)
#define MIN(a,b) (a)>(b)?(b):(a)
#define ll long long int
#define ull unsigned long long int
#define INF 10000000

int n, l, m;
char s[51][51];
int num[51];

void input() {
	scanf("%d", &n);

	for (int i = 0; i < n; i++)
	{
		scanf("%s", s[i]);
	}
	l = strlen(s[0]);

	char tmp[51];
	strcpy(tmp, s[0]);

	m = l;

	for (int i = 1; i < l; i++)
	{
		char t = tmp[0];

		for (int j = 1; j < l; j++)
		{
			tmp[j - 1] = tmp[j];
		}
		tmp[l - 1] = t;

		if (strcmp(tmp, s[0]) == 0)
		{
			m = i;
			break;
		}
	}



}

int numbering() {
	memset(num, -1, sizeof(num));
	num[0] = 0;

	for (int i = 1; i < n; i++)
	{
		for (int j = 0; j < l; j++)
		{
			bool f = true;
			for (int k = 0; k < l; k++)
			{
				int cur = (j + k) % l;
				if (s[0][k] != s[i][cur])
				{
					f = false;
					break;
				}
			}

			if (f)
			{
				num[i] = j;
				break;
			}
		}
		if (num[i] == -1)
			return -1;
	}
	return 0;
}

int main() {
	input();

	if (numbering() == -1)
		printf("-1\n");
	else {
		int ans = INF;

		for (int i = 0; i < l; i++)
		{
			int sum = 0;

			for (int j = 0; j < n; j++)
			{
				int tmp = num[j] - i;
				if (tmp < 0) tmp += l;
				sum += tmp % m;
			}
			ans = MIN(ans, sum);
		}

		if(ans != INF)
			printf("%d\n", ans);
		else printf("-1\n");
	}

	return 0;
}