TASK DEFINITION: Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.
PROBLEM: canada day is a national and an official holiday in canada celebrating its anniversary of confederation.

SOLUTION: canada day

PROBLEM: hadstock is a village and civil parish in uttlesford, essex, england.

SOLUTION: hadstock

PROBLEM: british hong kong is the old hong kong when it was under the administration of the british empire.

SOLUTION:
british hong kong