You are given a code:

def main_solution(x):
    return func_20(func_5('wetb', 'nde'), func_15('umyzj'))

Can you predict the output of `main_solution("mdr")` 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": "mdr"}, "ref_output": "n\u00abdue\u00bbw\u00abemt\u00bbb\u00aby\u00bb\u00abz\u00bb\u00abj\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_5('wetb', 'nde'), func_15('umyzj'))", "funcname": "main_solution"}
rule