You are given a code:

def main_solution(x):
    return (func_15('lprav') + func_13('vhlrb', '|'))

Can you predict the output of `main_solution("zpi")` 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": "zpi"}, "ref_output": "\u00abl\u00bb\u00abp\u00bb\u00abr\u00bb\u00aba\u00bb\u00abv\u00bbv|h|l|r|b", "ref_code": "def main_solution(x):\n    return (func_15('lprav') + func_13('vhlrb', '|'))", "funcname": "main_solution"}
rule