Step 1: Divide the number into separate digits:
42949 => 4 2 9 4 9
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
4 to 2 = 2
2 to 9 = 7
9 to 4 = 5
4 to 9 = 5
9 to 4 = 5
Step 3: Combine the filters to a string:
2 7 5 5 5 = 27555