// includes
#include <bits/stdc++.h>

// macros
#define ll long long int
#define pb emplace_back
#define mk make_pair
#define pq priority_queue
#define FOR(i, a, b) for(int i=(a);i<(b);++i)
#define rep(i, n) FOR(i, 0, n)
#define rrep(i, n) for(int i=((int)(n)-1);i>=0;i--)
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end())
#define FI first
#define SE second
using namespace std;

//  types
typedef pair<int, int> P;
typedef pair<ll, int> Pl;
typedef pair<ll, ll> Pll;
typedef pair<double, double> Pd;
 
// constants
const int inf = 1e9;
const ll linf = 1LL << 50;
const double EPS = 1e-10;
const int mod = 1e9 + 7;

// solve
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(a > b){a = b; return 1;} return 0;}
template <typename T> istream &operator>>(istream &is, vector<T> &vec){for(auto &v: vec)is >> v; return is;}

string s[7];

int main(int argc, char const* argv[])
{
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  rep(i, n)cin >> s[i];
  vector<int> w(n, 0);
  vector<P> vec;
  rep(i, n){
    rep(j, n){
      if(s[i][j] == 'o')w[i]++;
      if(s[i][j] == '-'){
        if(i < j)vec.pb(mk(i, j));
      }
    }
  }
  int res = inf;
  for(int i = 0; i < (1 << sz(vec)); i++){
    vector<int> win = w;
    for(int j = 0; j < sz(vec); j++){
      if((i >> j) % 2 == 1){
        win[vec[j].FI]++;
      }else{
        win[vec[j].SE]++;
      }
    }
    vector<P> p(n);
    rep(i, n)p[i] = mk(win[i], i);
    sort(all(p), [](auto x, auto y){return x.FI > y.FI;});
    set<int> st;
    rep(i, n){
      if(p[i].SE == 0){
        int tmp = sz(st) + 1;
        if(st.find(p[i].FI) != st.end())tmp--;
        res = min(res, tmp);
        break;
      }else{
        st.insert(p[i].FI);
      }
    }
  }
  cout << res << endl;
	return 0;
}