Step 1: Divide the number into separate digits:
99574 => 9 9 5 7 4
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
9 to 9 = 0
9 to 5 = 4
5 to 7 = 2
7 to 4 = 3
4 to 9 = 5
Step 3: Combine the filters to a string:
0 4 2 3 5 = 04235