You are given a code:

def main_solution(x):
    return (func_13(x, '_') + func_20('alud', 'sizs'))

Can you predict the output of `main_solution("hcporqpkb")` 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": "hcporqpkb"}, "ref_output": "h_c_p_o_r_q_p_k_basliuzds", "ref_code": "def main_solution(x):\n    return (func_13(x, '_') + func_20('alud', 'sizs'))", "funcname": "main_solution"}
rule