#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <queue>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>

using namespace std;

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;
typedef unsigned long long ULL;

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(auto i: c)
#define SORT(c) sort((c).begin(),(c).end())

#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()

const double EPS = 1e-10;
const double PI  = acos(-1.0);

#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int N;
	cin >> N;
	vector<string> S(N);
	REP(i, N) cin >> S[i];

	int ret = 100;
	function<void()> f = [&](){
		int a = -1, b = -1;
		REP(i, N) REP(j, N){
			if(S[i][j] == '-'){
				a = i, b = j;
				break;
			}
			if(a != -1 && b != -1) break;
		}

		if(a == -1 && b == -1){
			VI score;
			int teamScore, rank;
			REP(i, N){
				int win = 0;
				REP(j, N){
					if(S[i][j] == 'o') win++;
				}
				if(i == 0) teamScore = win;
				if(find(ALL(score), win) == score.end()) score.push_back(win);
			}
			sort(ALL(score), greater<int>());
			REP(i, score.size()) if(score[i] == teamScore){
				rank = i + 1;
			}
			ret = min(ret, rank);
		}
		else{
			S[a][b] = 'o';
			S[b][a] = 'x';
			f();
			S[a][b] = 'x';
			S[b][a] = 'o';
			f();
			S[a][b] = '-';
			S[b][a] = '-';
		}
	};

	f();

	cout << ret << endl;

	return 0;
}