You are given a code:

def main_solution(x):
    return (func_15('axdur') + func_13('cmaer', '_'))

Can you predict the output of `main_solution("xzkbrwh")` 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": "xzkbrwh"}, "ref_output": "\u00aba\u00bb\u00abx\u00bb\u00abd\u00bb\u00abu\u00bb\u00abr\u00bbc_m_a_e_r", "ref_code": "def main_solution(x):\n    return (func_15('axdur') + func_13('cmaer', '_'))", "funcname": "main_solution"}
rule