Step 1: Divide the number into separate digits:
36799 => 3 6 7 9 9
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
3 to 6 = 3
6 to 7 = 1
7 to 9 = 2
9 to 9 = 0
9 to 3 = 6
Step 3: Combine the filters to a string:
3 1 2 0 6 = 31206