You are given a code:

def main_solution(x):
    return func_20(func_20(x, 'vslvz'), func_15('uclfga'))

Can you predict the output of `main_solution("btcquvho")` 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": "btcquvho"}, "ref_output": "b\u00abvut\u00bbs\u00abccl\u00bbq\u00abvlu\u00bbz\u00abvfh\u00bbo\u00abg\u00bb\u00aba\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_20(x, 'vslvz'), func_15('uclfga'))", "funcname": "main_solution"}
rule