You are given a code:

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

Can you predict the output of `main_solution("xenjbpa")` 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": "xenjbpa"}, "ref_output": "x\u00abexn\u00bbj\u00abbep\u00bba\u00abgnb\u00bba\u00abj\u00bb\u00abb\u00bb\u00abp\u00bb\u00aba\u00bb", "ref_code": "def main_solution(x):\n    return func_20((x + 'gba'), func_15(x))", "funcname": "main_solution"}
rule