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.

Ex Input:
the karlal (urdu کرڑال also known as kard'al, karaal, karhral, or kiraal) is a hindko speaking tribe in khyber-pakhtunkhwa, pakistan.

Ex Output:
karlal


Ex Input:
cartagena (pronounced /kartaˈçena/ in spanish; the usual english pronunciation is /ˌkaːtəˈheɪnə/ or /ˌkaɹɾəˈheɪnə/), also known as cartagena de indias ("cartagena of the west indies"), is a large city seaport on the northern coast of colombia.

Ex Output:
cartagena de indias


Ex Input:
malaysia airlines flight 370 (mh370, also named under a codeshare agreement as china southern airlines flight cz748) is a missing malaysia airlines international passenger flight.

Ex Output:

malaysia airlines flight 370