You are given a code:

def main_solution(x):
    return (func_23('nsfrkg', 2) + ('rmfld' + 'hrpdvv'))

Can you predict the output of `main_solution("rnvcecabu")` 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": "rnvcecabu"}, "ref_output": "nsfrkg1rmfldhrpdvv", "ref_code": "def main_solution(x):\n    return (func_23('nsfrkg', 2) + ('rmfld' + 'hrpdvv'))", "funcname": "main_solution"}
rule