public static int hourglassSum(List<List<Integer>> arr) {
        int biggest = Integer.MIN_VALUE;
        for(int i = 0; i < arr.size() - 2; i++){
            for(int j = 0; j < arr.get(i).size() - 2; j++){
                int count = 0;
                count += arr.get(i).get(j);
                count += arr.get(i).get(j + 1);
                count += arr.get(i).get(j + 2);
                count += arr.get(i + 1).get(j + 1);
                count += arr.get(i + 2).get(j);
                count += arr.get(i + 2).get(j + 1);
                count += arr.get(i + 2).get(j + 2);
                biggest = count >= biggest ? count : biggest;
            }
        }
        return biggest;
    }