You are given a code:

def main_solution(x):
    return func_20(func_15(x), func_15('llmuif'))

Can you predict the output of `main_solution("lfcjnf")` 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": "lfcjnf"}, "ref_output": "\u00ab\u00abll\u00bb\u00bb\u00ab\u00abfl\u00bb\u00bb\u00ab\u00abcm\u00bb\u00bb\u00ab\u00abju\u00bb\u00bb\u00ab\u00abni\u00bb\u00bb\u00ab\u00abff\u00bb\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15(x), func_15('llmuif'))", "funcname": "main_solution"}
rule