You are given a code:

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

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