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.

Input: Consider Input: paranthropus is an extinct genus of robust australopithecines.

Output: paranthropus


Input: Consider Input: painting is using colours to make art.

Output: painting


Input: Consider Input: an undersea cable or submarine communications cable is a cable that is laid in the sea or in waterways.


Output: undersea cable