You are given a code:

def main_solution(x):
    return ('nnlxnw' + x)

Can you predict the output of `main_solution("gkmbbula")` 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": "gkmbbula"}, "ref_output": "nnlxnwgkmbbula", "ref_code": "def main_solution(x):\n    return ('nnlxnw' + x)", "funcname": "main_solution"}
rule