You are given a code:

def main_solution(x):
    return func_11(func_5('urj', 'ro'), 3)

Can you predict the output of `main_solution("ulmbofc")` 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": "ulmbofc"}, "ref_output": "urxum", "ref_code": "def main_solution(x):\n    return func_11(func_5('urj', 'ro'), 3)", "funcname": "main_solution"}
rule