#include<bits/stdc++.h>
using namespace std;
using ll = long long;

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl
#define p_yes() p("Yes")
#define p_no() p("No")

const ll mod = 1e9 + 7;
const ll inf = 1e18;

template < typename T >
void vprint(T &V){
	for(auto v : V){
    	cout << v << " ";
	}
	cout << endl;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    // input
    ll N;
    cin >> N;

    vector<string> S(N);
    FOR(i, 0, N){
        cin >> S.at(i);
    }

    ll rank = inf;

    FOR(mask, 0, 1<<15){
        ll k = -1;
        map<ll, ll> mp;

        FOR(i, 0, N){
            FOR(j, i+1, N){
                k++;
                if(S[i][j]=='-'){
                    if(mask>>k & 1){
                        mp[i]++;
                    }else{
                        mp[j]++;
                    }
                }
                else if(S[i][j]=='o'){
                        mp[i]++;
                }
                else{
                    mp[j]++;
                }
            }
        }

        // 結果集計
        set<ll> se;
        FOR(i, 0, N){
            ll win = mp[i];
            se.insert(win);
        }
        ll player_win = mp[0];
        ll dist = distance(se.begin(), se.lower_bound(player_win));
        ll order = se.size() - dist;

        chmin(rank, order);
    }

    p(rank);
    
    return 0;
}