You are given a code:

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

Can you predict the output of `main_solution("mtqdc")` 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": "mtqdc"}, "ref_output": "\u00abmmt\u00bbq\u00abdtc\u00bbe\u00abrqw\u00bbz\u00abpdt\u00bb\u00abc\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15(x), (x + 'erwzpt'))", "funcname": "main_solution"}
rule