#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define llong long long

int getresult(vector<string> &m) {
    vector<int> wins(m.size(), 0);
    rep(i, m.size()) rep(j, m.size()) if(m[i][j] == 'o') wins[i] += 1;
    int val = wins[0];
    sort(wins.begin(), wins.end(), greater<int>());
    unique(wins.begin(), wins.end());
    int ret = distance(wins.begin(), find(wins.begin(), wins.end(), val)) + 1;
    return ret;
}

int main() {
    int n;
    cin >> n;
    vector<string> m(n);
    rep(i, n) cin >> m[i];

    int rests = 0;
    rep(i, n) rep(j, n) if(m[i][j] == '-') rests += 1;
    rests /= 2;
    int result = n;
    if(rests > 0) {
        rep(i, 1 << rests) {
            bitset<20> bits(i);
            vector<string> base = m;
            int counter = 0;
            for(int ii=0; ii<n; ii++) {
                for(int jj=ii+1; jj<n; jj++) {
                    if(base[ii][jj] == '-') {
                        if(bits.test(counter) == 1) {
                            base[ii][jj] = 'o';
                            base[jj][ii] = 'x';
                        } else {
                            base[ii][jj] = 'x';
                            base[jj][ii] = 'o';
                        }
                        counter++;
                    }
                }
            }
            result = min(getresult(base), result);
        }
    } else {
        result = min(getresult(m), result);
    }

    cout << result << "\n";
}