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

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    int N; cin >> N;
    vector<string> S(N);
    rep(i,N) cin >> S[i];

    vector<pair<int,int>> P;
    rep(j,N)rep(i,j) if(S[i][j] == '-') P.push_back({i, j});
    
    int K = P.size();
    int Ans = N;
    rep(T,1<<K) {
        rep(i,K) {
            auto [x, y] = P[i];
            S[x][y] = (T & (1 << i) ? 'o' : 'x');
            S[y][x] = (S[x][y] ^ 'o' ^ 'x');
        }

        vector<int> cnt(N, 0);
        rep(i,N)rep(j,N)if(i != j) cnt[i] += (S[i][j] == 'o');
        set<int> st(cnt.begin(), cnt.end());
        int rank = 1;
        for(auto it = st.rbegin(); it != st.rend(); it++) {
            if(*it == cnt[0]) break;
            rank++;
        }
        Ans = min(Ans, rank);
    }

    cout << Ans << endl;
}