You are given a code:

def main_solution(x):
    return func_20(func_1(x, 3), func_15(x))

Can you predict the output of `main_solution("vmltvvhg")` 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": "vmltvvhg"}, "ref_output": "v\u00abmvl\u00bbt\u00abvmv\u00bbh\u00abglv\u00bbm\u00abltt\u00bbv\u00abvvh\u00bbg\u00abvvm\u00bbl\u00abthv\u00bbv\u00abhgg\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_1(x, 3), func_15(x))", "funcname": "main_solution"}
rule