You are given a code:

def main_solution(x):
    return func_20(func_15(x), func_19('nffhnz', 2))

Can you predict the output of `main_solution("ruxyybentz")` 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": "ruxyybentz"}, "ref_output": "\u00abfrh\u00bbn\u00abzun\u00bbf\u00abx\u00bb\u00aby\u00bb\u00aby\u00bb\u00abb\u00bb\u00abe\u00bb\u00abn\u00bb\u00abt\u00bb\u00abz\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15(x), func_19('nffhnz', 2))", "funcname": "main_solution"}
rule