Step 1: Divide the number into separate digits:
1165 => 1 1 6 5
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
1 to 1 = 0
1 to 6 = 5
6 to 5 = 1
5 to 1 = 4
Step 3: Combine the filters to a string:
0 5 1 4 = 0514