#include<iostream>
using namespace std;
int main(void)
{
	int i, j, k, ans = 0, hu = 0, n, m = 0, pa[105] = { 0 };
	char a[105][105][33], h[10] = "nyanpass";

	cin >> n;
	for (j = 1; j <= n; j++) {

		for (i = 1; i <= n; i++)

			cin >> a[j][i];
		for (k = 0; k < 8; k++) {
			m = 0;
			if (a[j][i][k] == h[k])
				m++;
			else break;
		
			if (m == 8) {
				pa[i]++;
			}
		}
	}
	int min = n - 1;
	for (i = 1; i <= n; i++)
		if (min == pa[i]) {
			ans = i;
			hu++;
		}
	if (hu != 1)ans = -1;
	cout << ans << endl;
	return 0;
}