You are given a code:

def main_solution(x):
    return func_20(func_13('ehfht', '_'), func_15(x))

Can you predict the output of `main_solution("ahvujdx")` 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": "ahvujdx"}, "ref_output": "e\u00ab_ah\u00bb_\u00abfh_\u00bbh\u00ab_vt\u00bb\u00abu\u00bb\u00abj\u00bb\u00abd\u00bb\u00abx\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_13('ehfht', '_'), func_15(x))", "funcname": "main_solution"}
rule