You are given a code:

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

Can you predict the output of `main_solution("jbfefvzjk")` 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": "jbfefvzjk"}, "ref_output": "z\u00abpnr\u00bbt\u00abscj\u00bbb\u00abfye\u00bbf\u00abvtz\u00bbj\u00abkg\u00bb\u00abb\u00bb", "ref_code": "def main_solution(x):\n    return func_20(('zprts' + x), func_15('ncytgb'))", "funcname": "main_solution"}
rule