Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

The Church of the Savior on Spilled Blood, built on the site of the assassination of Tsar Alexander II, is in which Russian city?
church of the savior on blood

Alejandro Amaya, Carlos Arruza, Jaime Bravo and Carmelo Torres are famous Mexican?
alejandro amaya

The Channel Islands are in which Channel?

channel islands