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: That's the kindest answer that I ever heard.
Example Output: acceptable

Example Input: The boy whose guardian's we elected employer president betrayed us.
Example Output: unacceptable

Example Input: San Francisco has been lived in by my brother.
Example Output:
unacceptable