You are given a code:

def main_solution(x):
    return func_20(('luhwt').lower(), func_15('gqkxun'))

Can you predict the output of `main_solution("spnnmz")` 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": "spnnmz"}, "ref_output": "l\u00abugh\u00bbw\u00abtq\u00bb\u00abk\u00bb\u00abx\u00bb\u00abu\u00bb\u00abn\u00bb", "ref_code": "def main_solution(x):\n    return func_20(('luhwt').lower(), func_15('gqkxun'))", "funcname": "main_solution"}
rule