You are given a code:

def main_solution(x):
    return func_20(func_15(x), (x + 'isi'))

Can you predict the output of `main_solution("ggxxpeols")` without writing any code? Please reason and put your final answer in the following json format: {"output": <your output>}, where <your output> should be the final string.
user
{"ref_input": {"x": "ggxxpeols"}, "ref_output": "\u00abggg\u00bbx\u00abxgp\u00bbe\u00aboxl\u00bbs\u00abixs\u00bbi\u00abp\u00bb\u00abe\u00bb\u00abo\u00bb\u00abl\u00bb\u00abs\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15(x), (x + 'isi'))", "funcname": "main_solution"}
rule