max_sum = -float("inf")

for i in range(4):
    for j in range(4):
        top = arr[i][j]+arr[i][j+1]+arr[i][j+2]
        middle = arr[i+1][j+1]
        bottom = arr[i+2][j]+arr[i+2][j+1]+arr[i+2][j+2]
        total = top + middle + bottom
        max_sum = max(max_sum, total)
return max_sum