bi dimentional array

fun hourglassSum(arr: Array<Array<Int>>): Int {

    val values = arrayListOf<Int>()

    for (i in 0 until (arr.size - 2)) {
        for (j in 0 until (arr[i].size - 2)) {
            val current = arr[i]
            val currentP1 = arr[i + 1]
            val currentP2 = arr[i + 2]
            val sum = current[j] + current[j + 1] + current[j + 2] + currentP1[j + 1] + currentP2[j] + currentP2[j + 1] + currentP2[j + 2]
            values.add(sum)
        }
    }
    return values.max()?:0
}