In this task, you're given an open-domain question. Your task is to provide an answer to the given question. There is only one unique answer for each question. Your answer should be short, and refer to an entity, date, number, etc. Do not put your answer in the context of a sentence.
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Question: Which unit is used to measure mass in the metric system?

Answer: kilogramme


Question: Who coined the phrase war to end all wars?

Answer: H. G. Wells


Question: How many dice are used in a standard game of backgammon?

Answer:
two