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".

[Q]: To behave oneself in public is expected.
[A]: acceptable


[Q]: It tries to be warm in September.
[A]: unacceptable


[Q]: I never have a pen when I need it.
[A]:
acceptable