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.

Example Input: ayman al-zawahiri is a former member of islamist organizations which have organised and carried out attacks in north america, asia, africa and the middle east.
Example Output: ayman al-zawahiri

Example Input: vehari district is a district in the punjab province of pakistan.
Example Output: vehari district

Example Input: land of the free is the national anthem of belize.
Example Output:
land of the free