You are given a code:

def main_solution(x):
    return func_13(('gbemob' + 'hvqcqi'), '_')

Can you predict the output of `main_solution("pxtdnubiq")` 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": "pxtdnubiq"}, "ref_output": "g_b_e_m_o_b_h_v_q_c_q_i", "ref_code": "def main_solution(x):\n    return func_13(('gbemob' + 'hvqcqi'), '_')", "funcname": "main_solution"}
rule