Step 1: Divide the number into separate digits:
33328 => 3 3 3 2 8
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
3 to 3 = 0
3 to 3 = 0
3 to 2 = 1
2 to 8 = 6
8 to 3 = 5
Step 3: Combine the filters to a string:
0 0 1 6 5 = 00165