Step 1: Divide the number into separate digits:
05978 => 0 5 9 7 8
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
0 to 5 = 5
5 to 9 = 4
9 to 7 = 2
7 to 8 = 1
8 to 0 = 8
Step 3: Combine the filters to a string:
5 4 2 1 8 = 54218