You are given a code:

def main_solution(x):
    return (func_4('zhvt') + ('xcaa' + 'ocwin'))

Can you predict the output of `main_solution("jcknvl")` 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": "jcknvl"}, "ref_output": "zhvtxcaaocwin", "ref_code": "def main_solution(x):\n    return (func_4('zhvt') + ('xcaa' + 'ocwin'))", "funcname": "main_solution"}
rule