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However , it was a beneficiary of the latter rivalry as both the Soviet Union and the United States vied for influence by building Afghanistan 's main highways , airports , and other vital infrastructure in the post-period .
 Soviet Union, United States, Afghanistan
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Soviet Union, United States, Afghanistan