Use of long long int in 2D Array

Question

What is the meaning of "Grid[i][1] = 1LL" in the following code?

typedef long long int ll;        
ll Grid[10][10];

for(i=1;i<4;i++)
{  
   if(Grid[i][1] == 0)   
   {  
      Grid[i][1] = 1LL;  
   }  
   else
      break;  
}