// In the name of Allah
#include <bits/stdc++.h>
#include "soccer.h"
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define F first
#define S second
#define endl '\n'
#define sep ' '
#define pb push_back
#define Mp make_pair
#define all(x) (x).begin(),(x).end()
#define len(x) ((ll) (x).size())
const int maxn = 2000 + 4;
const int oo = 1e9 + 7;
int n;
int A[maxn][maxn];
vector<pii> ls;
int val1[maxn][maxn], val2[maxn][maxn];
pii val[maxn]; int dp[maxn][maxn];
pii valx[maxn][maxn];
bool cmp(pii i, pii j) {
return ((i.S - i.F) > (j.S - j.F));
}
bool is_ok() {
ls.clear();
for (int i = 0; i < n; i++) {
int x = 0;
for (int j = 0; j < n; j++) {
if (A[i][j] != A[i][x]) {
if (A[i][x] == 0) ls.pb(Mp(x, j - 1));
x = j;
}
}
if (A[i][x] == 0) ls.pb(Mp(x, n - 1));
}
sort(all(ls), cmp);
for (int i = 1; i < len(ls); i++) {
if (ls[i].F < ls[i - 1].F || ls[i].S > ls[i - 1].S) return 0;
}
return 1;
}
int check() {
int num = 0;
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) num += (A[i][j] == 0);
}
bool ok = 1;
ok &= is_ok();
for (int i = 0; i < n; i++) {
for (int j = i; j < n; j++) swap(A[i][j], A[j][i]);
}
ok &= is_ok();
for (int i = 0; i < n; i++) {
for (int j = i; j < n; j++) swap(A[i][j], A[j][i]);
}
if (ok) return num;
else return 0;
}
int get_val(int y) {
for (int x = 0; x < n; x++) {
if (A[x][y] == 1) val[x] = Mp(n, -1);
else val[x] = Mp(val1[x][y], val2[x][y]);
}
int res = 0;
for (int ln = 1; ln <= n; ln++) {
for (int l = 0, r = ln - 1; r < n; l++, r++) {
if (ln == 1) {
valx[l][r] = val[l];
if (valx[l][r].F > valx[l][r].S) dp[l][r] = -oo;
else dp[l][r] = (valx[l][r].S - valx[l][r].F + 1);
}
else {
valx[l][r] = val[l];
valx[l][r].F = max(valx[l][r].F, valx[l + 1][r].F);
valx[l][r].S = min(valx[l][r].S, valx[l + 1][r].S);
if (valx[l][r].F > valx[l][r].S) dp[l][r] = -oo;
else dp[l][r] = (valx[l][r].S - valx[l][r].F + 1) + max(dp[l + 1][r], dp[l][r - 1]);
}
dp[l][r] = max(dp[l][r], -oo);
res = max(res, dp[l][r]);
}
}
return res;
}
int solve() {
int mx = 0;
for (int j = 0; j < n; j++) {
mx = max(mx, get_val(j));
}
return mx;
}
int biggest_stadium(int N, vector<vector<int>> F) {
n = N;
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
A[i][j] = F[i][j];
if (A[i][j] == 1) ls.pb(Mp(i, j));
}
}
if (len(ls) == 0) return (n * n);
else if (len(ls) == 1) {
int i = ls.back().F, j = ls.back().S;
return (n * n) - (min(i + 1, n - i) * min(j + 1, n - j));
}
for (int i = 0; i < n; i++) {
int x = 0;
for (int j = 0; j < n; j++) {
if (A[i][j] != A[i][x]) x = j;
val1[i][j] = x;
}
x = n - 1;
for (int j = n - 1; j >= 0; j--) {
if (A[i][j] != A[i][x]) x = j;
val2[i][j] = x;
}
}
if (n <= 500) return solve();
else return check();
}
