You are given a code:

def main_solution(x):
    return func_20(func_13(x, '_'), func_15('opoliu'))

Can you predict the output of `main_solution("togkdxmzdb")` 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": "togkdxmzdb"}, "ref_output": "t\u00ab_oo\u00bb_\u00abgp_\u00bbk\u00ab_od\u00bb_\u00abxl_\u00bbm\u00ab_iz\u00bb_\u00abdu_\u00bbb", "ref_code": "def main_solution(x):\n    return func_20(func_13(x, '_'), func_15('opoliu'))", "funcname": "main_solution"}
rule