int biggestSum = Integer.MIN_VALUE;

     for(int i = 0; i< arr.size()-2 ;i++){
        List<Integer>  firstRow = arr.get(i);
        List<Integer> secondRow = arr.get(i+1);
        List<Integer> ThirdRow = arr.get(i+2);

         for(int j =0; j<arr.size()-2; j++){
          int  hourGlassSum = 
          firstRow.get(j) + firstRow.get(j+1) + firstRow.get(j+2)+
          secondRow.get(j+1)+
          ThirdRow.get(j)+ThirdRow.get(j+1)+ThirdRow.get(j+2);

            biggestSum= Math.max(hourGlassSum, biggestSum);
         }  
    }

          System.out.println(biggestSum);