You are given a code:

def main_solution(x):
    return func_13(func_9('mosjgr'), '_')

Can you predict the output of `main_solution("wgssn")` 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": "wgssn"}, "ref_output": "m_o_s_j_g_r_r_g_j_s_o_m", "ref_code": "def main_solution(x):\n    return func_13(func_9('mosjgr'), '_')", "funcname": "main_solution"}
rule