#include <bits/stdc++.h>
using namespace std;

int main(void) {
	int N;
	cin >> N;
	vector<string> S(N);
	for(int i = 0; i < N; ++i) cin >> S[i];
	
	vector<pair<int, int>> v;
	for(int i = 0; i < N; ++i) for(int j = i + 1; j < N; ++j) if(S[i][j] == '-') v.push_back(make_pair(i, j));
	int M = v.size();
	
	int ans = 1e9;
	for(int bit = 0; bit < (1 << M); ++bit) {
		vector<string> T = S;
		for(int i = 0; i < M; ++i) {
			auto [x, y] = v[i];
			T[x][y] = 'o', T[y][x] = 'x';
			if(bit >> i & 1) swap(T[x][y], T[y][x]);
		}
		
		vector<int> cnt(N, 0);
		for(int i = 0; i < N; ++i) for(int j = 0; j < N; ++j) if(T[i][j] == 'o') ++cnt[i];
		
		set<int> s;
		for(int i = 0; i < N; ++i) if(cnt[i] > cnt[0]) s.insert(cnt[i]);
		
		ans = min(ans, (int)s.size() + 1);
	}
	
	cout << ans << "\n";
	
	return 0;
}