#include <iostream>
#include <algorithm>
#include <string>
using namespace std;

int main()
{
    int n;
    while (cin>>n) {
        vector<string> a(n);
        for(auto& s: a) cin>>s;

        vector<pair<int, int>> x;
        for(int i=0;i<n;++i) for(int j=i+1;j<n;++j)
            if (a[i][j]=='-') x.emplace_back(i, j);

        int res=100;
        int m=x.size();
        for(int i=0;i<(1<<m);++i) {
            for(int j=0;j<m;++j) {
                int p, q; tie(p, q)=x[j];
                if (i&(1<<j)) {
                    a[p][q]='o'; a[q][p]='x';
                }
                else {
                    a[p][q]='x'; a[q][p]='o';
                }
            }
            vector<int> b(n);
            for(int i=0;i<n;++i) b[i]=count(begin(a[i]), end(a[i]), 'x');
            int x=b[0];

            sort(begin(b), end(b));
            b.erase(unique(begin(b), end(b)), end(b));
            for(int i=0;i<b.size();++i) if (b[i]==x) res=min(res, i+1);
        }
        cout<<res<<endl;
    }
}