Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.

Example Input: It's pretty nice and comes with a little book with interesting proverbs too. I'm not sure if it really helps to relieve stress but it's makes a fun distraction once in a while. The only complaint is when other people play around with it, they always spill sand out the box..
Example Output: Positive

Example Input: What am I reviewing here... this gizmo or the supplier, Eforcity? I never received this product after my order! After waiting and waiting I contacted Eforcity several times -- no reply. After a nasty letter from me Eforcity'r reply feigned lacking information about my mailing address!What a cop-out.I told them I would not pay for it, so Eforcity said they'd give me a refund, which has not come to me yet. I bought another product to replace this from Amazon which arrived quickly from Amazon.
Example Output: Negative

Example Input: I'm sure this product is great for G4 Powebooks and G3 iBooks, but nowhere in this product description does it say that this adapter is NOT for use with iBook G4s. I tried this on my iBook G4, and the computer kept switching back and forth between battery power and the power supply from the adapter. I'm returning this to Amazon tomorrow, but am upset that I wasted $20 overnighting this adapter because I absolutely need to use my computer this weekend. I wish they would update the product description to make it explicit that this is for Powerbook G4s and iBook G3s ONLY.
Example Output:
Negative