You are given a code:

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

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