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: She speaks enough clearly to be understood.
Example Output: unacceptable

Example Input: It seemed to rain.
Example Output: acceptable

Example Input: I know a man who John is as tall as.
Example Output:
acceptable