#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <sstream>
#include<set>
#include<stack>

//#include<bits/stdc++.h>


using namespace std;



int main() {
	
	int n;
	cin >> n;

	vector<string>p(n);
	for (int i = 0; i < n; i++)cin >> p[i];

	
	vector<int> a(n);
	vector<pair<int, int>>d;

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (p[i][j] == 'o')a[i]++;
			if (p[i][j] == '-') {
				if (i > j)continue;
				d.push_back(make_pair(i, j));

			}
		}
	}

	int ans = 10;

	for (int i = 0; i < 1 << d.size(); i++) {
		vector<string>t = p;
		vector<int>b(n);

		for (int j = 0; j < d.size(); j++) {
			int x = d[j].first;
			int y = d[j].second;
		//	cout << x << " " << y << endl;
			if (j&i) {
				b[x]++;
				
			}
			else b[y]++;
		}
		for (int j = 0; j < n; j++) {
			b[j] += a[j];
			//cout << b[j] << endl;
		}
		int r = b[0];
		int w = 1;
		sort(b.rbegin(), b.rend());
		
		for (int j = 0; j < n; j++) {
		//	cout << b[j];
			if (j) {
				
				if (b[j - 1] > b[j])w++;
				
			}if (b[j] == r)break;
		}
		//cout << r << endl;;
		ans = min(w, ans);

	}

	cout << ans << endl;

	return 0;


		
}