You are given a code:

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

Can you predict the output of `main_solution("tgdxjgm")` 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": "tgdxjgm"}, "ref_output": "t_g_d_x_j_g_m\u00abs\u00bb\u00abj\u00bb\u00abm\u00bb\u00abp\u00bb\u00abg\u00bb", "ref_code": "def main_solution(x):\n    return (func_13(x, '_') + func_15('sjmpg'))", "funcname": "main_solution"}
rule