#include "bits/stdc++.h"
using namespace std;
#define ll long long int
#define rep(i,n) for( int i = 0; i < n; i++ )
#define rrep(i,n) for( int i = n; i >= 0; i-- )
#define REP(i,s,t) for( int i = s; i <= t; i++ )
#define RREP(i,s,t) for( int i = s; i >= t; i-- )
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define INF 2000000000
#define mod 1000000007
#define INF2 1000000000000000000

int N;
char s[6][6];

int rk(char a[6][6]) {
	int score[N] = {};
	rep(i, N) rep(j, N) if (s[i][j] == 'o') score[i]++;
	int tmp = score[0];
	sort(score, score + N, greater<int>());
	int rank = 1;
	int j = 0;
	//rep(i, N) cout << score[i] << " ";
	//cout << endl;
	while(true) {
		int k = score[j];
		if (k == tmp) return rank;
		while (k == score[j]) j++;
		rank++;
	}
}

int ans = 6;

void dfs(char a[6][6]) {
	int R = N;
	int flag = true;
	rep(i, N) {
		rep(j, N) {
			if (a[i][j] == '-') {
				flag = false;
				a[i][j] = 'o';
				a[j][i] = 'x';
				dfs(a);
				a[i][j] = 'x';
				a[j][i] = 'o';
				dfs(a);
			}
		}
	}
	if (flag) {
		//cout << rank(a) << endl;
		ans = min(ans, rk(a));
	}
}

int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
	cin >> N;
	rep(i, N) rep(j, N) cin >> s[i][j];
	dfs(s);
	cout << ans << endl;




    return 0;
}