There are set of strings. In the first for loop
1 is replaced with
In the next for loop, output strings after doing above replacement are combined with
z in between them.
In the final string,
z is replaced with
a. This final string is compared with our input hash.
04a5a2af0eb53473a4a2efb3dafa02df is the hash we get. Decrypting that in crackstation we get the string