You are given a code:

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

Can you predict the output of `main_solution("zdo")` 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": "zdo"}, "ref_output": "u\u00abbzq\u00bba\u00abzdd\u00bbo\u00abo\u00bb", "ref_code": "def main_solution(x):\n    return func_20(('ubqa' + x), func_15(x))", "funcname": "main_solution"}
rule