You are given a code:

def main_solution(x):
    return (func_13('kdqpxj', '_') + func_15('yyefiq'))

Can you predict the output of `main_solution("bijvrhsn")` 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": "bijvrhsn"}, "ref_output": "k_d_q_p_x_j\u00aby\u00bb\u00aby\u00bb\u00abe\u00bb\u00abf\u00bb\u00abi\u00bb\u00abq\u00bb", "ref_code": "def main_solution(x):\n    return (func_13('kdqpxj', '_') + func_15('yyefiq'))", "funcname": "main_solution"}
rule