#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

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

    int ans = 100;

    string s[n];
    rep(i,n)cin >> s[i];

    int m = n * (n-1) / 2;

    rep(i,1<<m){
        int ii = i;
        int f[m] = {};
        rep(j,m){
            f[j] = ii % 2;
            ii /= 2;
        }
        int cnt = 0;
        string t[n];
        rep(j,n)t[j] = s[j];
        rep(j,n){
            srep(k,j+1,n){
                if(t[i][j] == '-'){
                    if(f[cnt]){
                        t[i][j] = 'o';
                        t[j][i] = 'x';
                    }else{
                        t[i][j] = 'x';
                        t[j][i] = 'o';
                    }
                }
                cnt++;
            }
        }
        int b[n+1] = {};
        rep(j,n){
            int c = 0;
            rep(k,n)if(t[j][k] == 'o')c++;
            b[c] = 1;
        }
        int c = 0;
        rep(k,n)if(t[0][k] == 'o')c++;
        int ju = 0;
        drep(j,n+1){
            if(b[j])ju++;
            if(c == j)ans = min(ans, ju);
        }
    }

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