Step 1: Divide the number into separate digits:
43227 => 4 3 2 2 7
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
4 to 3 => 1
3 to 2 => 1
2 to 2 => 0
2 to 7 => 5
7 to 4 => 3
Step 3: Convert distances to codes (0=E[qual],
1 & 9 = C[onsecutive], 2-8 = N[one]):
1 => C
1 => C
0 => E
5 => N
3 => N
Step 4: Combine the filters to a string:
C C E N N = CCENN