You are given a code:

def main_solution(x):
    return (func_4('bupgms') + func_13('qsymk', '-'))

Can you predict the output of `main_solution("cbkz")` 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": "cbkz"}, "ref_output": "bupgmsq-s-y-m-k", "ref_code": "def main_solution(x):\n    return (func_4('bupgms') + func_13('qsymk', '-'))", "funcname": "main_solution"}
rule