Instruct: Classify an Amazon review as either positive or negative.
Query: good

The product is really good and educational. My only concern is that I orderedwith my PR address of 30 years and they cancelled my order, because it was not a valid address. (I shop with that same address at Amazon for about 10 years, and always received my merchandise) Then, I have to ordered with my son address at Ohio, and then he mailed me to Puerto Rico at my same address. I paid double shipping of course because of that problem. Otherwise the product is good.