Instructions: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
Input: Who was Minister-Chairman of the Russian Provisional Government and Prime Minister of Russia from 21 July 1917 (following the abdication of Tsar Nicholas II) to 8 November 1917 (the Bolshevik revolution), who is buried in Putney Vale Cemetery, London?
Output:
russian revolution