#include <iostream>
#include <sstream>
#include <math.h>
#include <vector>
#include <array>
#include <algorithm>
#include <queue>
#include <numeric>
#include <map>
#include <set>

using namespace std;
#define int long long
#define FOR(i, a, b) for(int i=(a);i<(b);i++)
#define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--)
#define REP(i, n) for(int i=0; i<(n); i++)
#define RREP(i, n) for(int i=(n-1); i>=0; i--)
#define ALL(a) (a).begin(),(a).end()
#define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end());
#define CONTAIN(a, b) find(ALL(a), (b)) != (a).end()
#define SUM(a) accumulate(ALL(a), 0)
#define array2(type, x, y) array<array<type, y>, x>
#define vector2(type) vector<vector<type> >
#define out(...) printf(__VA_ARGS__)

typedef pair<int, int> pos;
int pos::*x = &pos::first;
int pos::*y = &pos::second;

int dxy[] = {0, 1, 0, -1, 0};

/*================================*/
int N;

char leag[6][6];

int minrank(char l[6][6]) {
    int fi, fj;
    fi = fj = -1;
    REP(i,N) REP(j,N) {
        if (l[i][j] == '-' && fi == -1) {
            fi = i;
            fj = j;
        }
    }
    if (fi == -1 && fj == -1) {
        int wins[7] = {0};
        int win0 = 0;
        // 全部埋まった
        REP(i,N) {
            int win = 0;
            REP(j,N) {
                if (l[i][j] == 'o') win++;
            }
            if (i == 0) win0 = win;
            wins[win]++;
        }
        int rank = 1;
        RFOR(i,0,6) {
            if (win0 == i) return rank;
            if (wins[i] > 0) rank++;
        }
    }
    int mrank = 7;
    l[fi][fj] = 'o';
    l[fj][fi] = 'x';
    mrank = min(mrank, minrank(l));
    l[fi][fj] = 'x';
    l[fj][fi] = 'o';
    mrank = min(mrank, minrank(l));
    l[fi][fj] = '-';
    l[fj][fi] = '-';
    return mrank;
}

signed main()
{
    cin >> N;
    string s;
    REP(i,N) {
        cin >> s;
        REP(j,N) leag[i][j] = s[j];
    }
    // 全探索
    cout << minrank(leag) << endl;
    
    return 0;
}