#include "soccer.h"
#include <bits/stdc++.h>
#define maxn 2005
using namespace std;
int n, f[maxn][maxn], s[maxn][maxn];
int xL[maxn][maxn], xR[maxn][maxn], xU[maxn][maxn], xD[maxn][maxn];
int biggest_stadium(int N, vector<vector<int>> F) {
n = N;
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++)
f[i][j] = F[i-1][j-1];
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++)
s[i][j] = s[i-1][j] + s[i][j-1] - s[i-1][j-1] + 1 - f[i][j];
function<int(int, int, int, int)> getRect = [&](int u, int v, int x, int y) {
return s[x][y] - s[u-1][y] - s[x][v-1] + s[u-1][v-1];
};
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++)
if (f[i][j]) {
xU[i][j] = getRect(1, j, i, j);
xD[i][j] = getRect(i, j, n, j);
xL[i][j] = getRect(i, 1, i, j);
xR[i][j] = getRect(i, j, i, n);
}
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++) {
xU[i][j] += xU[i-1][j] + xU[i][j-1] - xU[i-1][j-1];
xD[i][j] += xD[i-1][j] + xD[i][j-1] - xD[i-1][j-1];
xL[i][j] += xL[i-1][j] + xL[i][j-1] - xL[i-1][j-1];
xR[i][j] += xR[i-1][j] + xR[i][j-1] - xR[i-1][j-1];
}
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++)
if (f[i][j]) {
if (getRect(1, j, i, j) && (xD[n][n] - xD[n][0] - xD[i-1][n] + xD[i-1][0])) return 0;
if (getRect(i, j, n, j) && xU[i][n]) return 0;
if (getRect(i, 1, i, j) && (xR[n][n] - xR[0][n] - xR[n][j-1] + xR[0][j-1])) return 0;
if (getRect(i, j, i, n) && xL[n][j]) return 0;
}
return s[n][n];
}
