Step 1: Divide the number into separate digits:
2562 => 2 5 6 2
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
2 to 5 = 3
5 to 6 = 1
6 to 2 = 4
2 to 2 = 0
Step 3: Combine the filters to a string:
3 1 4 0 = 3140