You are given a code:

def main_solution(x):
    return (func_23(x, 2) + func_15('nxpl'))

Can you predict the output of `main_solution("utoo")` 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": "utoo"}, "ref_output": "utoo1\u00abn\u00bb\u00abx\u00bb\u00abp\u00bb\u00abl\u00bb", "ref_code": "def main_solution(x):\n    return (func_23(x, 2) + func_15('nxpl'))", "funcname": "main_solution"}
rule