You are given a code:

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

Can you predict the output of `main_solution("uogirxrboo")` 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": "uogirxrboo"}, "ref_output": "u_o_g_i_r_x_r_b_o_o_c_w_z_e", "ref_code": "def main_solution(x):\n    return func_13((x + 'cwze'), '_')", "funcname": "main_solution"}
rule