You are given a code:

def main_solution(x):
    return ((x + x) + func_13('flsdf', '|'))

Can you predict the output of `main_solution("jstbac")` 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": "jstbac"}, "ref_output": "jstbacjstbacf|l|s|d|f", "ref_code": "def main_solution(x):\n    return ((x + x) + func_13('flsdf', '|'))", "funcname": "main_solution"}
rule