#include<stdio.h>
#include<stdlib.h>
#define MAX_SIZE 1001{
   int row;
   int col;
   int dist;
  }Cell;
   Cell queue [MAX_SIZE * MAX_SIZE];
   int front=0,rear=0;
   int drow[]={-1,1,0,0}
   int dcol[]={0,0,-1,1}
   int M,N;
   int grid[MAX_SIZE][MAX_SIZE];
   int visited[MAX_SIZE][MAX_SIZE];