You are given a code:

def main_solution(x):
    return (func_23('koe', 2) + func_13('fzaj', '-'))

Can you predict the output of `main_solution("yrbkxhz")` 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": "yrbkxhz"}, "ref_output": "koe1f-z-a-j", "ref_code": "def main_solution(x):\n    return (func_23('koe', 2) + func_13('fzaj', '-'))", "funcname": "main_solution"}
rule