Given reviews from Amazon, classify those review based on their content into two classes: Negative or 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: What else can I say? All that love CB should own this DVD. I love Charlie Brown and this is a true Christmas classic.
Example Output: Positive

Example Input: This Frankenstein series started off with 3 1/2 stars and deteriorated downward with every new volume. Not up to Mr. Koontz's standard of edge of your seat, nail biting suspense I've come to love.
Example Output:
Negative