You are given a code:

def main_solution(x):
    return func_20(func_19(x, 2), func_15('vpznpt'))

Can you predict the output of `main_solution("ckdtvgls")` 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": "ckdtvgls"}, "ref_output": "d\u00abtvv\u00bbg\u00ablps\u00bbc\u00abkz\u00bb\u00abn\u00bb\u00abp\u00bb\u00abt\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_19(x, 2), func_15('vpznpt'))", "funcname": "main_solution"}
rule