/*
     * Complete the 'hourglassSum' function below.
     *
     * The function is expected to return an INTEGER.
     * The function accepts 2D_INTEGER_ARRAY arr as parameter.
     */

    public static int hourglassSum(List<List<Integer>> arr) {
    // Write your code here
    int max = Integer.MIN_VALUE;
    for (int i = 0; i < 4; i++) {
        int actual = 0;
        for (int j = 0; j < 4; j++) {
            actual = arr.get(i).get(j) + arr.get(i).get(j+1)+ arr.get(i).get(j+2)+
                     arr.get(i+1).get(j+1)+
                     arr.get(i+2).get(j)+arr.get(i+2).get(j+1)+arr.get(i+2).get(j+2);
            if(actual > max){
                max = actual;
            }             
            
        }
    }
    return max;

    }