Step 1: Divide the number into separate digits:
85051 => 8 5 0 5 1
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
8 to 5 = 3
5 to 0 = 5
0 to 5 = 5
5 to 1 = 4
1 to 8 = 7
Step 3: Combine the filters to a string:
3 5 5 4 7 = 35547