You are given a code:

def main_solution(x):
    return func_20(func_20(x, x), func_15('biqr'))

Can you predict the output of `main_solution("nelbzpjle")` 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": "nelbzpjle"}, "ref_output": "n\u00abnbe\u00bbe\u00ablil\u00bbb\u00abbqz\u00bbz\u00abprp\u00bbjjllee", "ref_code": "def main_solution(x):\n    return func_20(func_20(x, x), func_15('biqr'))", "funcname": "main_solution"}
rule