Step 1: Divide the number into separate digits:
4763 => 4 7 6 3
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
4 to 7 = 3
7 to 6 = 1
6 to 3 = 3
3 to 4 = 1
Step 3: Combine the filters to a string:
3 1 3 1 = 3131