You are given a code:

def main_solution(x):
    return (func_13('frrted', '-') + func_15(x))

Can you predict the output of `main_solution("wokb")` 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": "wokb"}, "ref_output": "f-r-r-t-e-d\u00abw\u00bb\u00abo\u00bb\u00abk\u00bb\u00abb\u00bb", "ref_code": "def main_solution(x):\n    return (func_13('frrted', '-') + func_15(x))", "funcname": "main_solution"}
rule