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.

a video projector takes a video signal and projects the corresponding image on a screen using a lens system.
video projector

habib thiam (21 january 1933 – 26 june 2017) was a senegalese politician.
habib thiam

the trans-karakoram tract is an area of nearly 5,180/ 5,800 km2 that was transferred by a border agreement from the pakistani-administered northern areas to china in 1963 with the proviso that the settlement was subject to the final solution of the kashmir dispute.

trans-karakoram tract