You are given a code:

def main_solution(x):
    return func_23(('qfa' + 'qcpbi'), 2)

Can you predict the output of `main_solution("mbbogmbsk")` 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": "mbbogmbsk"}, "ref_output": "qfaqcpbi1", "ref_code": "def main_solution(x):\n    return func_23(('qfa' + 'qcpbi'), 2)", "funcname": "main_solution"}
rule