You are given a code:

def main_solution(x):
    return func_20((x + x), func_13('kjozkq', '_'))

Can you predict the output of `main_solution("ldcund")` 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": "ldcund"}, "ref_output": "lkd_cju_nod_lzd_cku_nqd", "ref_code": "def main_solution(x):\n    return func_20((x + x), func_13('kjozkq', '_'))", "funcname": "main_solution"}
rule