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: Bob proved that this set is recursive.
Example Output: acceptable

Example Input: We peered around the room.
Example Output: acceptable

Example Input: John is tough to persuade.
Example Output:
acceptable