You are given a code:

def main_solution(x):
    return func_5(func_13(x, '_'), 'kxw')

Can you predict the output of `main_solution("xwvghfduiq")` 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": "xwvghfduiq"}, "ref_output": "kxwx_w_v_g_h_f_d_u_i_q", "ref_code": "def main_solution(x):\n    return func_5(func_13(x, '_'), 'kxw')", "funcname": "main_solution"}
rule