You are given a code:

def main_solution(x):
    return func_17(func_13('pdaos', '_'))

Can you predict the output of `main_solution("piilv")` 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": "piilv"}, "ref_output": "s_o_a_d_p", "ref_code": "def main_solution(x):\n    return func_17(func_13('pdaos', '_'))", "funcname": "main_solution"}
rule