You are given a code:

def main_solution(x):
    return func_20(func_15('svtkdl'), (x + 'gjej'))

Can you predict the output of `main_solution("nfyaug")` 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": "nfyaug"}, "ref_output": "\u00abnsf\u00bby\u00abavu\u00bbg\u00abgtj\u00bbe\u00abjk\u00bb\u00abd\u00bb\u00abl\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15('svtkdl'), (x + 'gjej'))", "funcname": "main_solution"}
rule