Step 1: Divide the number into separate digits:
32754 => 3 2 7 5 4
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
3 to 2 = 1
2 to 7 = 5
7 to 5 = 2
5 to 4 = 1
4 to 3 = 1
Step 3: Combine the filters to a string:
1 5 2 1 1 = 15211