#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];
	vector<int> tree[n];
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
			if(f[i][j])
			{
				tree[i].push_back(j);
			}
		}
	}
	for(int i = 0; i < n; i++)
	{
		lg bef = 0, aft = 0;
		for(auto it : tree[i])
		{
			lg x = it;
			while(x >= 0)
			{
				bef += !f[i][x];
				x--;
			}
			x = it;
			while(x < n)
			{
				aft += !f[i][x];
				x++;
			}
		}
		if(bef && aft)	pos = 0;
		tree[i].clear();
	}
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
			if(f[i][j])
			{
				tree[j].push_back(i);
			}
		}
	}
	for(int i = 0; i < n; i++)
	{
		lg bef = 0, aft = 0;
		for(auto it : tree[i])
		{
			lg x = it;
			while(x >= 0)
			{
				bef += !f[x][i];
				x--;
			}
			x = it;
			while(x < n)
			{
				aft += !f[x][i];
				x++;
			}
		}
		if(bef && aft)	pos = 0;
	}
	return (pos ? ans : -1);
}