#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cstring>

typedef long long ll;
using namespace std;

#define mod 1000000009
#define INF 10000000
#define LLINF 2000000000000000000LL

#define SIZE 10001

int n,point[6];
char s[6][8];
vector<pair<int,int> > vec;

int dfs(int h){
    int a,b;
    
    if(h==vec.size()){
        int rank=1;
        vector<int> result;
        for(int i=1;i<n;i++)
            result.push_back(point[i]);
        
        sort(result.begin(),result.end());
        
        for(int i=1;i<n;i++){
            if(point[i]>point[0] && point[i]!=point[i-1])
                rank++;
        }
        
        return rank;
    }
    
    point[vec[h].first]++;
    a = dfs(h+1);
    point[vec[h].first]--;
    point[vec[h].second]++;
    b = dfs(h+1);
    point[vec[h].second]--;
    
    return min(a,b);
}

int main(){
    
    
    scanf("%d",&n);
    
    for(int i=0;i<n;i++)
        scanf("%s",s[i]);
    
    
    for(int i=0;i<n;i++){
        for(int j=i+1;j<n;j++){
            if(s[i][j]=='-'){
                vec.push_back({i,j});
            }else if(s[i][j]=='o'){
                point[i]++;
            }else{
                point[j]++;
            }
        }
    }
    
    printf("%d\n",dfs(0));
    
    return 0;
}