#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, pii> P;

const ll INF = 1ll<<29;
const ll MOD = 1000000007;
const double EPS  = 1e-10;

int n;
string s[6];

int main() {
	cin >> n;
	REP(i, n) cin >> s[i];
	
	vector<pii> v;
	REP(i, n) FOR(j, i + 1, n) if (s[i][j] == '-')
		v.push_back(pii(i, j));
	
	int win[6] = {};
	REP(i, n) REP(j, n) if (s[i][j] == 'o') win[i]++;
	
	int ans = INF;
	
	if (v.empty()) {
		set<int> ss;
		FOR(i, 1, n) if (win[i] > win[0]) ss.insert(win[i]);
		ans = ss.size() + 1;
	}
	
	REP(i, 1<<v.size()) {
		int cnt[6];
		copy(win, win + n, cnt);
		
		REP(j, v.size()) {
			if (i >> j & 1) cnt[v[j].first]++;
			else cnt[v[j].second]++;
		}
		
		set<int> ss;
		FOR(j, 1, n) if (cnt[j] > cnt[0]) ss.insert(cnt[j]);
		
		chmin(ans, ss.size() + 1);
	}
	
	cout << ans << endl;
	
	return 0;	
}