35596
Practical examples of this approach are the GNU Compiler Collection , Clang ( LLVM-based C / C ++ compiler ) , and the Amsterdam Compiler Kit , which have multiple front-ends , shared optimizations and multiple back-ends .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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