You are given a code:

def main_solution(x):
    return (func_20('vvw', x) + func_4('kwunrh'))

Can you predict the output of `main_solution("nlldl")` 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": "nlldl"}, "ref_output": "vnvlwldlkwunrh", "ref_code": "def main_solution(x):\n    return (func_20('vvw', x) + func_4('kwunrh'))", "funcname": "main_solution"}
rule