$totalrow = count($grid);
    
    $columnArr = array();
    $allIndex = array();

    for ($i=0; $i <$totalrow ; $i++) { 
         $arr = str_split($grid[$i]);
         $columnArr[]  = $arr;
    }
    $columnLength = count($columnArr[0]);


    for ($i=1; $i < $totalrow-1; $i++) { 

        for ($j=1; $j <$columnLength-1 ; $j++) { 
            $rowis = $i+1;
            $columnIs = $j+1;
            
            $down = $totalrow-$rowis;
            $up = $totalrow - ($down +1);
            $right = $columnLength - ($columnIs);
            $left = $columnLength - ($right+1);
            $min = min($down,$up,$right,$left);
            
            
            for ($k=$min; $k >0 ; $k--) { 
                
                 $totalValue = 0;
                 $flag = 0;
                 $indexArr = array();
                 $innerArr = array();
                 for ($l=0; $l <$k; $l++) { 
                     
                     
                      $val = $l+1;
                      $newupRow = $rowis -$val-1;
                      $newDownRow = $rowis+$val-1;
                     
                      $columnUpValue = $columnArr[$newupRow][$columnIs-1];
                     

                      $columnDownvalue = $columnArr[$newDownRow][$columnIs-1];
                     

                     
                      $colLeft = ($columnIs-1)-($l+1);
                       $columnLeftValue = $columnArr[$rowis-1][$colLeft];
                      

                       $colRight = ($columnIs-1)+($l+1);
                        $columnRightValue = $columnArr[$rowis-1][$colRight];
                     

                       if($columnUpValue === 'G' && $columnDownvalue === 'G' && $columnLeftValue === 'G' && $columnRightValue === 'G' && $columnArr[$i][$j] === 'G' && $l === 0 )
                        {
                            $flag = 1;
                            $totalValue+= 4;
                       
                         $innerArr[] =$newupRow.','.$columnIs-1;
                         $innerArr[] =$newDownRow.','.$columnIs-1;
                         $innerArr[] =($rowis-1).','.$colLeft;
                         $innerArr[] =($rowis-1).','.$colRight;
                         $innerArr[] =$i.','.$j;

                        }
                        else if($columnUpValue === 'G' && $columnDownvalue === 'G' && $columnLeftValue === 'G' && $columnRightValue === 'G'  && $columnArr[$i][$j] === 'G' && $flag === 1 )
                        {
                            $flag = 1;
                            $totalValue+= 4;
                        
                        $innerArr[] =$newupRow.','.$columnIs-1;
                         $innerArr[] =$newDownRow.','.$columnIs-1;
                         $innerArr[] =($rowis-1).','.$colLeft;
                         $innerArr[] =($rowis-1).','.$colRight;
                       
                       
                        }
                         else
                        {
                            break;
                        }

                       if(count($innerArr)>0)
                       {
                            $indexArr[] = $innerArr;

                       } 


                 }
                
                
                   if(count($indexArr)>0)
                       {
                            $allIndex[] = $indexArr;

                       } 
                  
                


            }
            
        }

        
    }


 
    

$result = array();
foreach ($allIndex as $outer) {
    foreach ($outer as $inner) {
        $result[] = $inner;
    }
}
    

    $unique = [];
foreach ($result as $sub) {
    $temp = $sub;
    sort($temp);                
    $key = json_encode($temp);  
    $unique[$key] = $sub;    
}


$result = array_values($unique);


$resultLen = count($result);

$ans = 0;
if ($resultLen == 1) {
    $ans = count($result[0]);
}
else
{
    $productArray = [];
for ($i=0; $i < $resultLen-1; $i++) { 
    
    $first = $result[$i];
    $firstLen = count($first);
    
     for ($j=$i+1; $j < $resultLen ; $j++) { 
        $second = $result[$j];
        $secondLen = count($second);

        $common = array_intersect($first, $second);

        if (!empty($common)) {
            $productArray[] = max($firstLen,$secondLen);
          
        } else {
            $secondLen = count($second);
            $productArray[] = $firstLen*$secondLen;
           
        }

     }
}

$ans = count($productArray) > 0 ? max($productArray) : 1;

}

return $ans;