You are given a code:

def main_solution(x):
    return ((x + x) + func_13('kzvcs', '_'))

Can you predict the output of `main_solution("lqpkfwz")` 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": "lqpkfwz"}, "ref_output": "lqpkfwzlqpkfwzk_z_v_c_s", "ref_code": "def main_solution(x):\n    return ((x + x) + func_13('kzvcs', '_'))", "funcname": "main_solution"}
rule