You are given a code:

def main_solution(x):
    return (func_20('lcvoyp', 'qnmsxv') + func_20('pmovei', 'vlcj'))

Can you predict the output of `main_solution("dtrbux")` 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": "dtrbux"}, "ref_output": "lqcnvmosyxpvpvmlocvjei", "ref_code": "def main_solution(x):\n    return (func_20('lcvoyp', 'qnmsxv') + func_20('pmovei', 'vlcj'))", "funcname": "main_solution"}
rule