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He bought $ 4 billion in prepositioning ships and $ 7 billion in ammo and equipment to fill them , and parked them at a new $ 6 billion base at Diego Garcia in the middle of the Indian Ocean .
 $ 4 billion, $ 7 billion, $ 6 billion, Diego Garcia, the Indian Ocean
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: date, organization, person, geographical social political, national religious political, facility, cardinal, location, work of art, law, event, product, ordinal, percent, time, quantity, money, language 
Text: {0} 
Answer:
 $ 4 billion, $ 7 billion, $ 6 billion, Diego Garcia, the Indian Ocean