You are given a code:

def main_solution(x):
    return func_20(func_15(x), func_15('jvut'))

Can you predict the output of `main_solution("ctxmngz")` 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": "ctxmngz"}, "ref_output": "\u00ab\u00abcj\u00bb\u00bb\u00ab\u00abtv\u00bb\u00bb\u00ab\u00abxu\u00bb\u00bb\u00ab\u00abmt\u00bb\u00bb\u00abn\u00bb\u00abg\u00bb\u00abz\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15(x), func_15('jvut'))", "funcname": "main_solution"}
rule