Given the task definition and input, reply with output. In this task, you're given a review from Amazon. Your task is to generate a rating for the product on a scale of 1-5 based on the review. The rating means 1: extremely poor, 2: poor, 3: neutral, 4: good, 5: extremely good.

Very nice. It was a little tricky as it didn't come with instructions but I looked at pictures and figured it out. I, too, added more stones as I didn't get many stones with the purchase. However, I purchased some stones at the dollar store and they work great. I am experimenting with different amounts of water as I like the sound of the water trickle.
4