#include <iostream>
#include <algorithm>
#include <vector>
#include <functional>
#include <queue>

using namespace std;

#define REP(i,first,last) for (int i=first;i<last;i++)

int n;
int result = 100000;
int win_count_0 = 0;

char game_results[6][6];
vector<char> game_results_pattern;

int main(){
  cin>>n;
  char val;
  //inputを表にする
  REP(i,0,n){
    REP(j,0,n){
      cin >> val;
      game_results[i][j] = val;
      // cout<<val<<" ";
    }
    // cout<<endl;
  }

  //0の残りの試合を負けて順位が上がる可能性
  //0の試合の残りを全て「勝ち」にして、勝ち数を保存しておく
  // REP(i,1,n){
  //   if (game_results[0][i] == 'o' || game_results[0][i] == '-') {
  //     game_results[0][i] = 'o';
  //     win_count_0 += 1;
  //   } 
  // }

  //game_results_patternに現状を記録
  REP(i,0,n){
    REP(j,i+1,n){
      game_results_pattern.push_back(game_results[i][j]);
    }
  }

  //queueで処理
  queue<vector<char>> que; 
  que.push(game_results_pattern);
  while (!que.empty()) {
    vector<char> q = que.front();
    // for(auto it=q.begin();it!=q.end();it++) {
    //   cout<<*it<<" ";
    // }
    // cout<<endl;
    que.pop();
    vector<char>::iterator it = find(q.begin(), q.end(), '-');
    if (it != q.end()) {
      q[it - q.begin()] = 'o';
      que.push(q);
      q[it - q.begin()] = 'x';
      que.push(q);
    } else {
      // for(auto it=q.begin();it!=q.end();it++) {
      //   cout<<*it<<" ";
      // }
      // cout<<endl;
      int c = 0;
      vector<int> points(6);
      REP(i,0,n){
        REP(j,i+1,n){
          if (q[c] == 'o') {
            points[i] += 1;
          } else {
            points[j] += 1;
          }
          c++;
        }
      }
      win_count_0 = points[0];
      // for (auto it=points.begin();it!=points.end();it++) {
      //   cout<<*it<<" ";
      // }
      // cout<<endl;
      sort(points.begin(), points.end(), greater<int>());
      points.erase(unique(points.begin(), points.end()), points.end());
      vector<int>::iterator it = find(points.begin(), points.end(), win_count_0);
      int new_result = it - points.begin() + 1;
      result = (new_result < result) ? new_result : result;
      // for (auto it=points.begin();it!=points.end();it++) {
      //   cout<<*it<<" ";
      // }
      // cout<<endl;
    }
  }
  cout<<result<<endl;
}