Step 1: Divide the number into separate digits:
3434 => 3 4 3 4
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
3 to 4 = 1
4 to 3 = 1
3 to 4 = 1
4 to 3 = 1
Step 3: Combine the filters to a string:
1 1 1 1 = 1111