You are given a code:

def main_solution(x):
    return func_20((x + 'csnbvg'), func_15(x))

Can you predict the output of `main_solution("cbkwubfv")` 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": "cbkwubfv"}, "ref_output": "c\u00abbck\u00bbw\u00abubb\u00bbf\u00abvkc\u00bbs\u00abnwb\u00bbv\u00abgu\u00bb\u00abb\u00bb\u00abf\u00bb\u00abv\u00bb", "ref_code": "def main_solution(x):\n    return func_20((x + 'csnbvg'), func_15(x))", "funcname": "main_solution"}
rule