#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;

typedef long long ll;
typedef unsigned long long ull;

static const double EPS = 1e-8;
static const double PI = 4.0 * atan(1.0);
static const double PI2 = 8.0 * atan(1.0);

#define REP(i,n)	for(int i=0;i<(int)n;++i)
#define ALL(c)		(c).begin(),(c).end()
#define CLEAR(v)	memset(v,0,sizeof(v))
#define MP(a,b)		make_pair((a),(b))
#define ABS(a)		((a)>0?(a):-(a))
#define FOR(i,s,n)	for(int i=s;i<(int)n;++i)

int N;
char s[6][6];

int solve(int pat) {
	char t[6][6];
	REP(i, N) REP(j, N) t[i][j] = s[i][j];
	int mask = 1;
	REP(i, N) FOR(j, i + 1, N) {
		if (t[i][j] == '-') {
			t[i][j] = ((pat & mask) != 0) ? 'o' : 'x';
			t[j][i] = (t[i][j] == 'o') ? 'x' : 'o';
		}
		mask <<= 1;
	}
	pair<int, int> win[6];
	REP(i, N) {
		win[i].first = 0;
		win[i].second = i;
	}
	REP(i, N) REP(j, N) if (t[i][j] == 'o') ++win[i].first;
	sort(win, win + N);
	reverse(win, win + N);
	int r = 1;
	int rank[6];
	REP(i, N) {
		if (i != 0 && win[i].first != win[i - 1].first) ++r;
		rank[win[i].second] = r;
	}
	return rank[0];
}

int main(int argc, char **argv) {
	cin >> N;
	REP(i, N) REP(j, N) cin >> s[i][j];
	int res = solve(0);
	REP(i, 1 << ((N - 1) * N / 2)) res = min(res, solve(i));
	cout << res << endl;
	return 0;
}