You are given a code:

def main_solution(x):
    return ((x + 'otfh') + func_13('ncofut', '_'))

Can you predict the output of `main_solution("kybompma")` 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": "kybompma"}, "ref_output": "kybompmaotfhn_c_o_f_u_t", "ref_code": "def main_solution(x):\n    return ((x + 'otfh') + func_13('ncofut', '_'))", "funcname": "main_solution"}
rule