Step 1: Divide the number into separate digits:
9383 => 9 3 8 3
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
9 to 3 = 6
3 to 8 = 5
8 to 3 = 5
3 to 9 = 6
Step 3: Combine the filters to a string:
6 5 5 6 = 6556