You are given a code:

def main_solution(x):
    return (func_3('vhtxl') + func_4('ncym'))

Can you predict the output of `main_solution("jbmu")` 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": "jbmu"}, "ref_output": "hltvxncym", "ref_code": "def main_solution(x):\n    return (func_3('vhtxl') + func_4('ncym'))", "funcname": "main_solution"}
rule