You are given a code:

def main_solution(x):
    return func_20(func_15('kguwyy'), func_20('mzhp', x))

Can you predict the output of `main_solution("ptnigdvvgb")` 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": "ptnigdvvgb"}, "ref_output": "\u00abmkp\u00bbz\u00abtgh\u00bbn\u00abpui\u00bbg\u00abdwv\u00bbv\u00abgyb\u00bb\u00aby\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15('kguwyy'), func_20('mzhp', x))", "funcname": "main_solution"}
rule