#include <iostream>
#include <string>
using namespace std;

int main() {
	int n, r = -1;
	cin >> n;
	for(int i=0; i<n; i++) {
		for(int j=1; j<=n; j++) {
			string a;
			cin >> a;
			
			if(a != "nyanpass")
				continue;

			if(r == -1) {
				r = j;
			}
			else if(r != j) {
				r = -1;
				break;
			}
		}
	}

	cout << r << endl;
}