Step 1: Divide the number into separate digits:
05039 => 0 5 0 3 9
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
0 to 5 = 5
5 to 0 = 5
0 to 3 = 3
3 to 9 = 6
9 to 0 = 9
Step 3: Combine the filters to a string:
5 5 3 6 9 = 55369