Step 1: Divide the number into separate digits:
98188 => 9 8 1 8 8
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
9 to 8 = 1
8 to 1 = 7
1 to 8 = 7
8 to 8 = 0
8 to 9 = 1
Step 3: Combine the filters to a string:
1 7 7 0 1 = 17701