#define _USE_MATH_DEFINES
#include <algorithm>
#include <cstdio>
#include <functional>
#include <iostream>
#include <cfloat>
#include <climits>
#include <cstring>
#include <cmath>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <vector>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<ll, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<ll, ll> ll_ll;
typedef pair<double, double> d_d;
struct edge { int u, v; ll w; };

ll MOD = 1000000007;
ll _MOD = 1000000009;
double EPS = 1e-10;
int INF = INT_MAX / 3;

int main() {
	int N; cin >> N;
	set<int> st;
	for (int i = 0; i < N; i++)
		for (int j = 0; j < N; j++) {
			string s; cin >> s;
			if (s == "nyanpass")
				st.insert(j);
		}
	if (st.size() == 1) cout << *st.begin() << endl;
	else cout << -1 << endl;
}