31873
Biography Boris Obukhov was born in 1891 in Kazan , before the Russian Revolution served as a naval officer and had a university degree .
 location: Kazan
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Kazan 
Answer:
 location: Kazan