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".

Penny rowed across the lake.
acceptable

I bought the parrot in the store.
acceptable

John believes that Fred likes steak that Joe likes pizza.

unacceptable