#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;

int N; vector<string> s; vector<pair<int, int>> pos;

int dfs(int depth)
{
	if (depth == 0)
	{
		vector<string> tmp = s;
		const string key = s[0];
		sort(s.begin(), s.end(), [](string i, string j){ return count(i.begin(), i.end(), 'o') > count(j.begin(), j.end(), 'o'); });
		for (int i = 0; i < N; ++i)
		{
			if (s[i] == key)
			{
				int counter = 0;
				for (int j = 0; j < i; ++j)
				{
					if (count(s[j].begin(), s[j].end(), 'o') == count(s[j + 1].begin(), s[j + 1].end(), 'o'))
						++counter;
				}
				s = tmp;
				return i + 1 - counter;
			}
		}
	}

	s[pos[depth - 1].first][pos[depth - 1].second] = 'o';
	s[pos[depth - 1].second][pos[depth - 1].first] = 'x';
	int a = dfs(depth - 1);
	s[pos[depth - 1].first][pos[depth - 1].second] = 'x';
	s[pos[depth - 1].second][pos[depth - 1].first] = 'o';
	int b = dfs(depth - 1);
	
	return min(a, b);
}

int main()
{
	cin >> N;
	for (int i = 0; i < N; ++i)
	{
		string tmp;
		cin >> tmp;
		s.push_back(tmp);
	}
	for (int i = 0; i < N; ++i)
	{
		for (int j = 0; j < i; ++j)
		{
			if (s[i][j] == '-')
				pos.push_back(pair<int, int>(i, j));
		}
	}

	cout << dfs(pos.size()) << endl;

	return 0;
}