You are given a code:

def main_solution(x):
    return (func_13(x, '_') + func_23('ylz', 1))

Can you predict the output of `main_solution("hjayijfsix")` 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": "hjayijfsix"}, "ref_output": "h_j_a_y_i_j_f_s_i_xylz1", "ref_code": "def main_solution(x):\n    return (func_13(x, '_') + func_23('ylz', 1))", "funcname": "main_solution"}
rule