You are given a code:

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

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