Step 1: Divide the number into separate digits:
07161 => 0 7 1 6 1
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
0 to 7 = 7
7 to 1 = 6
1 to 6 = 5
6 to 1 = 5
1 to 0 = 1
Step 3: Combine the filters to a string:
7 6 5 5 1 = 76551