#include <stdio.h>
#include <iostream>
#include <string>
#include <vector>
#include <set>
#include <cmath>
#include <stack>
#include <algorithm>
#include <iomanip>
#include <map>
#include <queue>
#include <functional>
#include <numeric>
#include <chrono>
#include <cstdlib>
using ll = long long;
using namespace std;

const ll MOD = 1e9 + 7;
#define REP(i, n) for (int(i) = 0; (i) < (n); ++(i))
#define repi(i, a, b) for (int i = int(a); i < int(b); ++i)
// bool operator<(const pair<int, int> &a, const pair<int, int> &b)
// {
//     if (a.first == b.first)
//         return a.second < b.second;
//     return a.first < b.first;
// };

/*unsigned int xor128(void)
{
    static unsigned int x = 123456789, y = 362436069, z = 521288629, w = 88675123;
    unsigned int t = (x ^ (x << 11));
    x = y;
    y = z;
    z = w;
    return (w = (w ^ (w >> 19)) ^ (t ^ (t >> 8)));
}
unsigned int xor128rnd(unsigned int m)
{
    return xor128() % m;
}*/

/*bool operator<(const pair<int, int> &a, const pair<int, int> &b)
{
    if (a.first == b.first)
    {
        return a.second < b.second;
    }
    return a.first < b.first;
}*/

int ans = 1000000;
int N;
void dfs(vector<string> &v)
{
    bool check = true;
    for (int i = 0; i < N; ++i)
    {
        for (int j = i + 1; j < N; ++j)
        {
            if (v[i][j] == '-')
            {
                check = false;
                v[i][j] = 'o';
                v[j][i] = 'x';

                dfs(v);
                v[i][j] = 'x';
                v[j][i] = 'o';
                dfs(v);
            }
        }
    }

    if (check)
    {

        int arr[N] = {0};
        for (int i = 0; i < N; ++i)
        {
            for (int j = 0; j < N; ++j)
            {
                if (v[i][j] == 'o')
                    arr[i]++;
            }
            //cout << arr[i] << endl;
        }
        int t = arr[0];
        sort(arr, arr + N);
        for (int i = N - 1; i >= 0; --i)
        {
            if (arr[i] == t)
            {
                ans = min(ans, N - i);
                break;
            }
        }
        return;
    }
}
int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);

    cin >> N;
    vector<string> v;
    for (int i = 0; i < N; ++i)
    {
        string s;
        cin >> s;
        v.push_back(s);
    }

    dfs(v);

    cout << ans << endl;
    return 0;
}