183715
Background During most of the latter half of the 20th century the two most powerful states in the world by far were the United States ( formed in 1783 ) and the Union of Soviet Socialist Republics ( formed in 1917 ) .
 United States, Union of Soviet Socialist Republics
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 United States, Union of Soviet Socialist Republics