You are given a code:

def main_solution(x):
    return func_20(func_15(x), func_9('mddla'))

Can you predict the output of `main_solution("xmtaqkn")` 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": "xmtaqkn"}, "ref_output": "\u00abmxd\u00bbd\u00ablma\u00bba\u00abltd\u00bbd\u00abma\u00bb\u00abq\u00bb\u00abk\u00bb\u00abn\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15(x), func_9('mddla'))", "funcname": "main_solution"}
rule