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: Willy is taller than Bill by as much as I know a boy who thinks that Bill is taller than Dan.

A: unacceptable
****
Q: John gave the books to Mary and the records to Sue.

A: acceptable
****
Q: I forgot to return the book that I borrowed from the teacher.

A:
acceptable
****