Characters

Your task is to modify a given string as follows:

1. Find the first position in the string that has two consecutive occurrences of the same character.
2. If there is no such position, exit.
3. Remove the two characters and replace them with a single character that is the next character in the alphabetical order. However, if the removed character is z, then the replacing character is a.
4. Return to step 1.

The string consists of the characters a-z and contains at most 10^5 characters.

In a file chars.py implement a function solve that returns the modified string.

def solve(s):
    # TODO

if __name__ == "__main__":
    print(solve("auto")) # auto
    print(solve("ddqqirr")) # eris
    print(solve("aaaaaa")) # cb
    print(solve("wsstuva")) # xa
    print(solve("zzzzzzzz")) # c
    print(solve("mlkjihgfedcbb")) # n
    print(solve("kkkjjiikjkjiikjjiijkjji")) # mjkjmlki

Explanation: For example, the string aaaaaa is modified as follows: aaaaaa \rightarrow baaaa \rightarrow bbaa \rightarrow caa \rightarrow cb