Step 1: Divide the number into separate digits:
23532 => 2 3 5 3 2
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
2 to 3 = 1
3 to 5 = 2
5 to 3 = 2
3 to 2 = 1
2 to 2 = 0
Step 3: Combine the filters to a string:
1 2 2 1 0 = 12210