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: John is prouder of having gone than John didn't expect me to believe he would be.
Example Output: unacceptable

Example Input: John remembered.
Example Output: acceptable

Example Input: Copper rods bend easily.
Example Output:
acceptable