You are given a code:

def main_solution(x):
    return (func_20('vmdiye', x) + func_20('pmtwf', x))

Can you predict the output of `main_solution("ckfnink")` 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": "ckfnink"}, "ref_output": "vcmkdfinyienkpcmktfwnfink", "ref_code": "def main_solution(x):\n    return (func_20('vmdiye', x) + func_20('pmtwf', x))", "funcname": "main_solution"}
rule