You are given a code:

def main_solution(x):
    return func_20(func_15('ccnih'), func_20('gfkfj', x))

Can you predict the output of `main_solution("btnxax")` 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": "btnxax"}, "ref_output": "\u00abgcb\u00bbf\u00abtck\u00bbn\u00abfnx\u00bbj\u00abaix\u00bb\u00abh\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15('ccnih'), func_20('gfkfj', x))", "funcname": "main_solution"}
rule