#define _USE_MATH_DEFINES
#include <algorithm>
#include <cstdio>
#include <functional>
#include <iostream>
#include <cstring>
#include <climits>
#include <cmath>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <vector>
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<ll, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<ll, ll> ll_ll;
typedef pair<double, double> d_d;
struct edge { int u, v; ll w; };
 
ll MOD = 1000000007;

int dx[4] = {-1, 0, 1, 0};
int dy[4] = {0, -1, 0, 1};

int main() {
	int N; cin >> N;
	vector<string> s(N);
	for (int i = 0; i < N; i++) cin >> s[i];
	int ans = N;
	for (int S = 0; S < (1<<15); S++) {
		vector<int> a(N); int k = 0;
		for (int i = 0; i < N; i++)
			for (int j = 0; j < i; j++) {
				if (s[i][j] == 'o' || (s[i][j] == '-' && S & (1<<k))) a[i]++;
				else a[j]++;
				k++;
			}
		int x = a[0];
		sort(a.begin(), a.end(), greater<int>());
		a.erase(unique(a.begin(), a.end()), a.end());
		ans = min(ans, (int)(find(a.begin(), a.end(), x) - a.begin()));
	}
	cout << ans + 1 << endl;
}