In this task, You are given a review of Amazon's food products. Your task is to divide them into two classes: negative or positive, depending on the content of the review.

Example Input: Since I badly need the 4:3 ratio for FPV flying, I will keep this unit. However, the USB power supply failed after second time I inserted it. Total junk design. However, opening up the unit, the connections for the supply are pretty obvious, and I think I can fix it. If you are not good at soldering iron, stay away from this equipment like hell, there is no way it would last longer than a couple of days, and there is a clear manufacturing failure. As far as quality (video) is concerned, it seemed to be OK, I have not noticed any major problems during the half-hour I was able to test out the unit. Quality is good, 4:3, 16:9 switchable, as advertized.
Example Output: negative

Example Input: flexible microwave lids in graduated sizes that fit inside one another through the central button handle - work well, excellent price. Anticipate they will be durable.
Example Output: positive

Example Input: Works wonders for my chronic back & shoulder pain, and even pain associated with endo. So glad I decided to try this unit. It is just as powerful as the one my mother received from her physical therapist's office. Very easy to use and I was very happy it comes with it's own carrying case. The unit is surprisingly light-weight and comes with leads, electrode sticky pads, battery, and charger. The device shuts off after a set amount of time so you don't have to worry about falling asleep with it on. Charges on standard usb charger. Easy for discreet wearing. I clip it onto the side of my pants and wear a long shirt to cover it. It does beep, but I haven't figured out yet if there's a way to shut the sound off. That's the only downside in my opinion. Arrived super quick. I was thankful for the one day shipping option because of the amount of pain I was in at the time of ordering. I still have to take pain meds, but not as frequently. It is a great supplement to my current pain management regimen. Very good value if you would like a tens and your insurance doesn't cover it.
Example Output:
positive