You are given a code:

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

Can you predict the output of `main_solution("qvnqgzeenv")` 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": "qvnqgzeenv"}, "ref_output": "q\u00abvqn\u00bbq\u00abgvz\u00bbe\u00abenn\u00bbv\u00abtqg\u00bbf\u00abcg\u00bb\u00abz\u00bb\u00abe\u00bb\u00abe\u00bb\u00abn\u00bb\u00abv\u00bb", "ref_code": "def main_solution(x):\n    return func_20((x + 'tgfc'), func_15(x))", "funcname": "main_solution"}
rule