1055
He signed numerous open letters protesting government policies in 1966 - 1973 and was expelled from the Communist Party of the Soviet Union in 1973 .
 organization: Communist Party of the Soviet Union
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 organization: Communist Party of the Soviet Union