<s>[INST] You are an assistant for question-answering tasks. Use the following pieces of retrieved context to answer the question. If you don't know the answer, just say that you don't know. Use three sentences maximum and keep the answer concise. Question:  What is a defibrillator used for? Context: A defibrillator is used to restore normal heart rhythm in cases of cardiac arrest. Answer: [/INST]A defibrillator is used to restore normal heart rhythm in cases of cardiac arrest.</s>