Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Kills the back of your ankle! OUCH!

The company touts their insert, and it's true. The insert is very nice, and helps keep your feet comfortable. HOWEVER, the shoe just KILLS your ankle/heel!! It literally rips up the skin at the back of my ankle and causes them to bleed. OUCH!I want to like them, but the pain is unbearable.