#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,popcnt,sse4,abm")
#include <bits/stdc++.h>
using namespace std;
#ifndef WAIMAI
#include "soccer.h"
#else
#include "grader.cpp"
#endif
#ifdef WAIMAI
#define debug(HEHE...) cout << "[" << #HEHE << "] : ", dout(HEHE)
void dout() {cout << '\n';}
template<typename T, typename...U>
void dout(T t, U...u) {cout << t << (sizeof...(u) ? ", " : ""), dout(u...);}
#else
#define debug(...) 7122
#endif
#define ll long long
#define Waimai ios::sync_with_stdio(false), cin.tie(0)
#define FOR(x,a,b) for (int x = a, I = b; x <= I; x++)
#define pb emplace_back
#define F first
#define S second
const int SIZE = 2005;
int n, ans;
bool a[SIZE][SIZE];
vector<pair<int, int>> p[SIZE];
int U[SIZE][SIZE], L[SIZE][SIZE], R[SIZE][SIZE], dp[SIZE][SIZE];
int biggest_stadium(int N, vector<vector<int>> F) {
n = N, ans = 0;
FOR (i, 1, n) p[i].clear();
FOR (i, 1, n) FOR (j, 1, n) a[i][j] = F[i - 1][j - 1], dp[i][j] = 0;
FOR (i, 1, n) {
FOR (j, 1, n) {
U[i][j] = (a[i][j] ? i : U[i - 1][j]);
L[i][j] = (a[i][j] ? j : L[i][j - 1]);
if (U[i][j] < i) p[i - U[i][j]].pb(i, j);
}
R[i][n + 1] = n + 1;
for (int j = n; j >= 1; j--) R[i][j] = (a[i][j] ? j : R[i][j + 1]);
}
FOR (ulen, 1, n) for (auto [x, y] : p[ulen]) {
if (ulen > 1) {
L[x][y] = max(L[x][y], L[x - 1][y]);
R[x][y] = min(R[x][y], R[x - 1][y]);
}
dp[x][y] = dp[x- 1][y] + (R[x][y] - L[x][y] - 1);
if (L[x][y] >= 1) dp[x][y] = max(dp[x][y], dp[x][L[x][y]] + (U[x][L[x][y]] - U[x][y]) * (R[x][y] - L[x][y] - 1));
if (R[x][y] <= n) dp[x][y] = max(dp[x][y], dp[x][R[x][y]] + (U[x][R[x][y]] - U[x][y]) * (R[x][y] - L[x][y] - 1));
ans = max(ans, dp[x][y]);
}
return ans;
}
/*
in1
5
0 0 0 0 0
1 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 1 0 0
out1
20
*/
