You're given a sentence and your task is to classify whether the sentence is acceptable or not. Any sentence which is grammatically correct, has a naturalistic text, is written by a native speaker and which minimizes superfluous content is acceptable, otherwise unacceptable. If the sentence is acceptable then write "acceptable", otherwise "unacceptable".

Example Input: When did you get back and what did you bring me?
Example Output: acceptable

Example Input: Mary came to read Fred's story, and I also came to.
Example Output: unacceptable

Example Input: By which Greek authors does he have books?
Example Output:
unacceptable