input question: Determine the topic of the question-answer pair. Question: "What is the purpose of North American Free Trade Agreement?";  Answer: "The North American Free Trade Agreement (NAFTA) is an agreement signed by Canada , Mexico , and the United States , creating a trilateral trade bloc in North America ."? Topic:???
output answer: North American Free Trade Agreement

Determine the topic of the question-answer pair. Question: "where is osaka japan?";  Answer: "Located at the mouth of the Yodo River on Osaka Bay , Osaka is Japan's third largest city by population after Tokyo (special wards) and Yokohama ."? Topic:
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Answer: Osaka

Q: Determine the topic of the question-answer pair. Question: "what is a constant in math??";  Answer: "A mathematical constant is a special number , usually a real number , that is "significantly interesting in some way"."? Topic:
A: Mathematical constant

Question: Determine the topic of the question-answer pair. Question: "what nationality is wendy williams?";  Answer: "Wendy Williams Hunter (born Wendy Joan Williams; July 18, 1964) is an American media personality , actress and author."? Topic:
Answer: Wendy Williams

[Q]: Determine the topic of the question-answer pair. Question: "what is the @ sign called??";  Answer: "The at sign @ is also commonly called the at symbol, ampersat, apetail or commercial at in English—and less commonly a wide range of other terms."? Topic:
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[A]: At sign

Problem: Given the question: Determine the topic of the question-answer pair. Question: "What is the disk defragmenter tool?";  Answer: "In the maintenance of file systems , defragmentation is a process that reduces the amount of fragmentation ."? Topic:
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The answer is:

Defragmentation