Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Not worth the purchase.

I'm quite disappointed with this book. I have been diligently reading it for the last week. At first, I noticed an abundance of typos. I just finished reading the OSPF chapters. Too much effort is wasted trying to figure out what the author is trying to say. The typos are now showing up in very critical areas. Information isn't consistent. After spending a very long time trying to understand the material, I realized that it was the authors presentation and typos that I was trying to work through not the actual material. Rather than waste anymore of my time, I'm going to purchase another book and start again.