#include<iostream>
#include<vector>
#include<string>
#include<algorithm>	
#include<map>
#include<set>
#include<utility>
#include<cmath>
#include<cstring>
#include<queue>
#include<stack>
#include<cstdio>
#include<sstream>
#include<iomanip>
#include<assert.h>
#include<ctime>
#include<cstdlib>
#include<numeric>
using namespace std;
typedef long long ll;
#define loop(i,a,b) for(ll i=a;i<b;i++)
#define rloop(i,a,b) for(int i=a;i>=b;i--)
const int inf=1e8;
const ll INF=1e16;
#define MOD 1000000007
#define mod 1000000009
#define m 1000003


int solve(vector< vector<char> > s);

int main(){
	int n;
	cin>>n;
	vector< vector<char> > s(n,vector<char>(n));
	loop(i,0,n){
		loop(j,0,n){
			cin>>s[i][j];
		}
	}
	int ans;
	ans=solve(s);
	cout<<ans<<"\n";
	return 0;
}

int solve(vector< vector<char> > s){
	int n=s.size();
	vector< vector<char> > s2=s;
	int cnt=0;
	loop(i,0,n){
		loop(j,0,n){
			if(s[i][j]=='-'){
				cnt++;
			}
		}
	}
	if(cnt==0){
		vector<int> win(n,0);
		loop(i,0,n){
			loop(j,0,n){
				if(s[i][j]=='o'){
					win[i]++;
				}
			}
		}
		int my_win=win[0];
		sort(win.begin(),win.end());
		reverse(win.begin(),win.end());
		int jun=1;
		int i=0;
		while(win[i]!=my_win){
			i++;
			if(win[i]!=win[i-1]){
				jun++;
			}
		}
		return jun;
	}else{
		loop(i,0,n){
			loop(j,0,n){
				if(s[i][j]=='-'){
					s[i][j]='o';s[j][i]='x';
					s2[i][j]='x';s2[j][i]='o';
					return min(solve(s),solve(s2));
				}
			}
		}
	}
}