#include "rect.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int>vi;
#define pb push_back
#define sz(x) (int)x.size()
#define all(x) begin(x),end(x)
#define FOR(i,a,b) for(int i=a; i<b; i++)
//-------------------
const int MX=2500+5;
const int dx[]={0,0,1,-1}, dy[]={1,-1,0,0};
void ckmax(int &x, int y){x=max(x,y);}
void ckmin(int &x, int y){x=min(x,y);}
int N,M;
vector<vi>a;
int vis[MX][MX];
int n=0, mnx, mxx, mny, mxy;
void dfs(int x, int y){
ckmax(mxx,x); ckmax(mxy,y);
ckmin(mnx,x); ckmin(mny,y);
n++;
vis[x][y]=1;
FOR(m,0,4){
int nx=x+dx[m], ny=y+dy[m];
if(min(nx,ny)>=0 && nx<N && ny<M && !vis[nx][ny] && !a[nx][ny])
dfs(nx,ny);
}
}
ll count_rectangles(vector<vi> a) {
N=sz(a); M=sz(a[0]);
::a=a;
memset(vis,0,sizeof(vis));
ll ans=0;
FOR(i,1,N-1) FOR(j,1,M-1) if(!a[i][j] && !vis[i][j]){
n=0;
mnx=10000, mxx=-1, mny=10000, mxy=-1;
dfs(i,j);
if(n==(mxx-mnx+1)*(mxy-mny+1)) ans++;
}
return ans;
/*ll ans=0;
FOR(i,1,N-1) FOR(j,1,M-1){
FOR(x,i,N-1) FOR(y,j,M-1){
int f=1;
FOR(xx,i,x+1){
FOR(yy,j,y+1){
f&=(a[xx][yy]<min(min(a[xx][j-1],a[xx][y+1]),min(a[i-1][yy],a[x+1][yy])));
if(!f) break;
}
if(!f) break;
}
ans+=f;
}
}
return ans; */
}
/*
6 5
4 8 7 5 6
7 4 10 3 5
9 7 20 14 2
9 14 7 3 6
5 7 5 2 7
4 5 13 5 6
*/
