You are given a code:

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

Can you predict the output of `main_solution("ympmylu")` 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": "ympmylu"}, "ref_output": "y\u00abrft\u00bbq\u00abyim\u00bbp\u00abmly\u00bbl\u00abua\u00bb\u00abu\u00bb", "ref_code": "def main_solution(x):\n    return func_20(('yrtq' + x), func_15('filau'))", "funcname": "main_solution"}
rule