You are given a code:

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

Can you predict the output of `main_solution("vibizi")` 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": "vibizi"}, "ref_output": "v_l_i_s_b_v_i_q_z_q_i", "ref_code": "def main_solution(x):\n    return func_13(func_20(x, 'lsvqq'), '_')", "funcname": "main_solution"}
rule