You are given a code:

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

Can you predict the output of `main_solution("lijmp")` 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": "lijmp"}, "ref_output": "lijmppdxw_k_e_f_v", "ref_code": "def main_solution(x):\n    return ((x + 'pdx') + func_13('wkefv', '_'))", "funcname": "main_solution"}
rule