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

[EX Q]: The title of this video mentions Argentine Tango. Unfortunately, what is being taught on this tape is not authentic Argentine Tango. Not even close. It's ballroom tango. There is a huge difference: in music, style, steps, posture, etc... Don't be fooled by ballroom instructors trying to teach Argentine Tango. The only authentic instruction available on the market comes from authentic Argentine instructors from Buenos Aires.
[EX A]: Negative

[EX Q]: Just "assembled" the bat cave for my 5 year old. Pathetic construction and workmanship -- half of the gimmics don't work. Another pile of injection-molded plastic parts and stickers that I get to assemble -- what is this thing -- $4 of raw materials + $2 of shipping + $10 of marketing? Garbage. Shame on you Mattel, the only thing worse is the batman figures with the batarangs that take 30 minutes and a blowtorch to get out of the packaging. This batcave will collapse and die within hours of play, I'm sure of it. GARBAGE!
[EX A]: Negative

[EX Q]: This book really disappointed me. It seems like a narrative. No real plot just a rambling repetitive narration of a poor island child. I wish I could say I loved it....but felt really let down.
[EX A]:
Negative