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: Ellen conferred to Helen.
Example Output: unacceptable

Example Input: With their teacher, the kids have arrived safely, hasn't he?
Example Output: unacceptable

Example Input: The paper provides many clues.
Example Output:
acceptable