You are given a code:

def main_solution(x):
    return func_20(func_15('jrvum'), func_1(x, 4))

Can you predict the output of `main_solution("tzas")` 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": "tzas"}, "ref_output": "\u00abtjz\u00bba\u00absrt\u00bbz\u00abavs\u00bbt\u00abzua\u00bbs\u00abtmz\u00bbas", "ref_code": "def main_solution(x):\n    return func_20(func_15('jrvum'), func_1(x, 4))", "funcname": "main_solution"}
rule