#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);

lg dx[] = {1, 0, -1, 0};
lg dy[] = {0, 1, 0, -1}, N;

lg valid(lg i, lg j)
{
	return i >= 0 && i < N && j >= 0 && j < N;
}


int biggest_stadium(int n, vector<vector<int>> f)
{
	N = n;
	lg pos = 1, ans = 0, sum = 0;
	for(int i = 0; i < n; i++)
		for(int j = 0; j < n; j++)
			ans += !f[i][j], sum += 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;
	}
	set<lg> se[5];
	//down, right, up, left
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
			if(f[i][j])	continue;
			if(i && j && f[i-1][j] && f[i][j-1])
			{
				auto it = se[4].lower_bound(i);
				if(it != se[4].begin())	pos = 0;
			}
			if(i+1 < n && j && f[i+1][j] && f[i][j-1])
			{
				auto it = se[4].upper_bound(i);
				if(it != se[4].end())	pos = 0;
			}
			if(i && f[i-1][j])
			{
				auto it = se[0].lower_bound(i);
				if(it != se[0].begin())	pos = 0;
			}
			if(i+1 < n && f[i+1][j])
			{
				auto it = se[2].upper_bound(i);
				if(it != se[2].end())	pos = 0;
			}
			if(j && f[i][j-1])
			{
				if(se[1].size())	pos = 0;
			}
			for(int k = 0; k < 4; k++)
			{
				lg newI = i+dx[k], newJ = j+dy[k];
				if(!valid(newI, newJ))	continue;
				if(f[newI][newJ])
				{
					se[k].insert((k%2 ? newI : newJ));
				}
			}
			se[4].insert(i);
		}
	}
	if(!pos)	ans = 1;
	if(sum == 1 && !pos)
	{
		int idI = 0, idJ = 0;
		for(int i = 0; i < n; i++)
		{
			for(int j = 0; j < n; j++)
			{
				if(f[i][j])
				{
					idI = i, idJ = j;
				}
			}
		}
		idI++;
		idJ++;
		// cout << idI << ' ' << idJ << '\n';
		// cout << idI*idJ << ' ' << idJ*(n-idI+1) << ' ' << idI*(n-idJ+1) << ' ' << (n-idJ+1)*(n-idI+1) << '\n';
		ans = n*n-min({idI*idJ, idJ*(n-idI+1), idI*(n-idJ+1), (n-idJ+1)*(n-idI+1)});
	}
	else if(n <= 3 && !pos)
	{
		for(int i = 0; i < (1ll << (n*n)); i++)
		{
			vector<array<lg, 2>> a;
			for(int j = 0; j < n*n; j++)
			{
				if((1ll << j)&i)
				{
					a.push_back({j/n, j%n});
				}
			}
			lg o = 1;
			for(auto it : a)
			{
				if(f[it[0]][it[1]])	o = 0;
				for(auto it2 : a)
				{
					if(it[0] == it2[0])
					{
						for(int j = min(it[1], it2[1]); j <= max(it[1], it2[1]); j++)
						{
							if(f[it[0]][j]) o = 0;
						}
						if(o)	continue;
					}
					if(it[1] == it2[1])
					{
						for(int j = min(it[0], it2[0]); j <= max(it[0], it2[0]); j++)
						{
							if(f[j][it[1]]) o = 0;
						}
						if(o)	continue;
					}
					lg d = 1, h = 1;
					if(!f[it[0]][it2[1]])	
					{
						for(int i = min(it[1], it2[1]); i <= max(it[1], it2[1]); i++)
						{
							if(f[it[0]][i])	d = 0;
						}
						for(int i = min(it[0], it2[0]); i <= max(it[0], it2[0]); i++)
						{
							if(f[i][it2[1]])	d = 0;
						}
						if(d)	continue;
					}
					if(!f[it2[0]][it[1]])	
					{
						for(int i = min(it[1], it2[1]); i <= max(it[1], it2[1]); i++)
						{
							if(f[it2[0]][i])	h = 0;
						}
						for(int i = min(it[0], it2[0]); i <= max(it[0], it2[0]); i++)
						{
							if(f[i][it[1]])	h = 0;
						}
						if(h)	continue;
					}
					o = 0;
					break;
				}
			}
			ans = max(ans, (lg)(o*a.size()));
		}
	}
	return ans;
}

int main()
{
	fastio;
	lg n;
	cin >> n;
	vector<vector<int>> v (n, vector<int> (n));
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
			cin >> v[i][j];
		}
	}
	cout << biggest_stadium(n, v) << '\n';

    return 0;
}

/usr/bin/ld: /tmp/cca4C6qJ.o: in function `main':
answer.code:(.text.startup+0x0): multiple definition of `main'; /tmp/ccwCPQaM.o:implementer.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status