Step 1: Divide the number into separate digits:
19305 => 1 9 3 0 5
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
1 to 9 = 8
9 to 3 = 6
3 to 0 = 3
0 to 5 = 5
5 to 1 = 4
Step 3: Combine the filters to a string:
8 6 3 5 4 = 86354