Instruct: Classify Amazon reviews into positive or negative sentiment
Query: WARNING!! Bad Grinder.

Krups does a great job with coffee makers. They should have stuck to what they do well. This is the worst coffee grinder I have ever had. After a few moments of grinding, this grinder will stop feeding beans into the grinding mechanism. You can shake it (which usually causes it to stop), you can remove and clean the grinding mechanism (as I just did)....Nothing helps. It grinds beans when it wants too and doesn't when it doesn't want to. Today it took 5 to 10 mins to grind the beans. Beating them between rocks would have been quicker.