You are given an open-domain question from an open movie database. Your task is to provide an answer to that question. Try to only include the answer. Do not put it in a sentence.

Let me give you an example: what kind of film is Best Seller?
The answer to this example can be: crime
Here is why: The answer is correct because crime genre movie is among best seller.

OK. solve this:
which movies was John Schalter a writer on?
Answer:
Safe House