#include <iostream>
using namespace std;

int main()
{
    int n;
    string a[100][100], b[100][100];
    bool isRenchon;
    int renchon = -1;

    cin >> n;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            cin >> a[i][j];
        }
    }

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            b[j][i] = a[i][j];
        }
    }

    for (int i = 0; i < n; i++) {
        isRenchon = true;

        for (int j = 0; j < n; j++) {
            if (b[i][j].compare("nyanpass") == 0 || b[i][j].compare("-") == 0) {
                isRenchon &= true;
            } else {
                isRenchon &= false;
            }
        }

        if (isRenchon) {
            if (renchon < 0) {
                renchon = i + 1;
            } else {
                renchon = -1;
                break;
            }
        }
    }

    cout << renchon << endl;

    return 0;
}