#include <bits/stdc++.h>
#ifndef CYBER
#include "soccer.h"
#endif
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#pragma GCC optimize("Ofast")

using namespace std;
using namespace __gnu_pbds;

#define lg long long
#define ordered_set	tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
#define fastio ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);

int biggest_stadium(int n, vector<vector<int>> f)
{
	lg pos = 1, ans = 0;
	for(int i = 0; i < n; i++)
		for(int j = 0; j < n; j++)
			ans += !f[i][j];
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
			if(f[i][j])	continue;
			for(int k = 0; k < n; k++)
			{
				for(int z = 0; z < n; z++)
				{
					if(f[k][z])	continue;
					if(i == k && j == z)	continue;
					if(i == k)
					{
						for(int g = min(j, z); g <= max(j, z); g++)
						{
							if(f[i][g])	pos = 0;
							if(!pos)	break;
						}
						continue;
					}
					if(j == z)
					{
						for(int g = min(i, k); g <= max(i, k); g++)
						{
							if(f[g][j])	pos = 0;
							if(!pos)	break;
						}
						continue;
					}
					lg l = min(i, k), r = max(i, k);
					if(!f[i][z])	continue;
					if(!f[k][j])	continue;
					pos = 0;
					break;
				}
				if(!pos)	break;
			}
			if(!pos)	break;
		}
		if(!pos)	break;
	}
	return (pos ? ans : -1);
}