You are given a code:

def main_solution(x):
    return func_13(func_20('hnpbcb', 'dbgcjw'), '_')

Can you predict the output of `main_solution("qgoibfw")` 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": "qgoibfw"}, "ref_output": "h_d_n_b_p_g_b_c_c_j_b_w", "ref_code": "def main_solution(x):\n    return func_13(func_20('hnpbcb', 'dbgcjw'), '_')", "funcname": "main_solution"}
rule