Instruct: Classify Amazon reviews into positive or negative sentiment
Query: This was one of the best written mysteries I've read.

This was one of the best written mysteries I've read in a long time. It kept me guessing and very interested from the beginning to the end. I couldn't put it down. It is obvious that she used her experiences as a student at Harvard as the basis for much of her information. Additionally, the protagonist's background was very similar to her personal educational background. There were no stereotypes and it was very realistic. For a first novel/mystery, it was excellent.