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".

The meeting began at 4 P.M.
acceptable

He has seen his children.
acceptable

I didn't read a single book the whole time I was in the library.

acceptable