You are given a code:

def main_solution(x):
    return func_13(('ixysoi' + 'pxibz'), '_')

Can you predict the output of `main_solution("pxqbqo")` 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": "pxqbqo"}, "ref_output": "i_x_y_s_o_i_p_x_i_b_z", "ref_code": "def main_solution(x):\n    return func_13(('ixysoi' + 'pxibz'), '_')", "funcname": "main_solution"}
rule