P2562 [AHOI2002] Kitty Cat Gene Encoding

Xiao Keke took an elective course in basic genetics. The professor told the class that on the planet Super Samuel, the lengths of Kitty cats’ genes are all positive integer powers of $2$, and they consist of two different gene units. These two different gene units are denoted as 0 and 1, so a Kitty cat’s gene can be written as a 01 string. To facilitate analysis and reduce storage, the professor invented the ABC encoding rule. This encoding repeatedly rewrites the Kitty cat gene’s 01 string according to  until it is finally rewritten into a string containing only the characters "A", "B", and "C".  Please write a program to help Xiao Keke compute the ABC encoding of a Kitty cat gene to assist the professor’s research.

The file contains one line, which is a 01 string representing a Kitty cat gene.

Output one line containing the ABC encoding of this Kitty cat gene.

The given 01 string length satisfies $Len \leq 256$. Translated by ChatGPT 5