#include "soccer.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
//mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll los(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;
struct block
{
int x1,x2,y1,y2,x3;
bool operator<(const block& other)
{
return (y2-y1) < (other.y2-other.y1);
}
};
int arr[2002][2002];
int pref[2002][2002];
vi ones[2002];
vector<block> blocks;
int ans = 0;
map<pii,int> ans_map[2002];
int biggest_stadium(int n, vector<vi> F)
{
rep2(i,0,n+2)
{
rep2(j,0,n+2)
{
arr[i][j] = 1;
}
}
rep2(i,1,n)
{
rep2(j,1,n)
{
arr[i][j] = F[i-1][j-1];
}
}
rep2(i,1,n)
{
rep2(j,1,n)
{
pref[i][j] = pref[i][j-1] + pref[i-1][j] - pref[i-1][j-1] + arr[i][j];
}
}
rep2(i,0,n+1)
{
rep2(j,1,n)
{
if(arr[i][j] == 1)
{
int p = i-1;
while(p >= 0 && arr[p][j] == 0)
{
int lb = j;
int rb = j;
int l = 1;
int r = j;
while(l <= r)
{
int mid = (l+r)/2;
if(pref[i-1][j]-pref[i-1][mid-1]-pref[p-1][j]+pref[p-1][mid-1] == 0)
{
lb = mid;
r = mid-1;
}
else
{
l = mid+1;
}
}
l = j;
r = n;
while(l <= r)
{
int mid = (l+r)/2;
if(pref[i-1][mid]-pref[i-1][j-1]-pref[p-1][mid]+pref[p-1][j-1] == 0)
{
rb = mid;
l = mid+1;
}
else
{
r = mid-1;
}
}
blocks.pb({lb,rb,p,i-1,j});
p--;
}
p = i+1;
while(p <= n && arr[p][j] == 0)
{
int lb = j;
int rb = j;
int l = 1;
int r = j;
while(l <= r)
{
int mid = (l+r)/2;
if(pref[p][j]-pref[p][mid-1]-pref[i][j]+pref[i][mid-1] == 0)
{
lb = mid;
r = mid-1;
}
else
{
l = mid+1;
}
}
l = j;
r = n;
while(l <= r)
{
int mid = (l+r)/2;
if(pref[p][mid]-pref[p][j-1]-pref[i][mid]+pref[i][j-1] == 0)
{
rb = mid;
l = mid+1;
}
else
{
r = mid-1;
}
}
blocks.pb({lb,rb,i+1,p,j});
p++;
}
}
}
}
rep(i,n+2)
{
rep(j,n+2)
{
if(arr[i][j] == 1) ones[j].pb(i);
}
}
sort(all(blocks));
forall(it,blocks)
{
int best = (it.x2-it.x1+1)*(it.y2-it.y1+1);
int l = 0;
int r = siz(ones[it.x1-1])-1;
int a = 0;
while(l <= r)
{
int mid = (l+r)/2;
if(ones[it.x1-1][mid] >= it.y1)
{
a = mid;
r = mid-1;
}
else
{
l = mid+1;
}
}
while(ones[it.x1-1][a-1] <= it.y2)
{
l = max(it.y1,ones[it.x1-1][a-1]+1);
r = min(it.y2,ones[it.x1-1][a]-1);
if(l <= r)
{
best = max(best,ans_map[it.x1-1][{l,r}]+(it.x2-it.x1+1)*(it.y2-it.y1+1)-(r-l+1)*(it.x2-it.x1+1));
}
a++;
}
l = 0;
r = siz(ones[it.x2+1])-1;
a = 0;
while(l <= r)
{
int mid = (l+r)/2;
if(ones[it.x2+1][mid] >= it.y1)
{
a = mid;
r = mid-1;
}
else
{
l = mid+1;
}
}
while(ones[it.x2+1][a-1] <= it.y2)
{
l = max(it.y1,ones[it.x2+1][a-1]+1);
r = min(it.y2,ones[it.x2+1][a]-1);
if(l <= r)
{
best = max(best,ans_map[it.x2+1][{l,r}]+(it.x2-it.x1+1)*(it.y2-it.y1+1)-(r-l+1)*(it.x2-it.x1+1));
}
a++;
}
ans = max(ans,best);
ans_map[it.x3][{it.y1,it.y2}] = max(ans_map[it.x3][{it.y1,it.y2}],best);
}
return ans;
}
