You are given a code:

def main_solution(x):
    return func_20((x).capitalize(), func_15('cmyizb'))

Can you predict the output of `main_solution("mfzvydg")` 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": "mfzvydg"}, "ref_output": "M\u00abfcz\u00bbv\u00abymd\u00bbg\u00aby\u00bb\u00abi\u00bb\u00abz\u00bb\u00abb\u00bb", "ref_code": "def main_solution(x):\n    return func_20((x).capitalize(), func_15('cmyizb'))", "funcname": "main_solution"}
rule