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:
dorothea sally eilers (or just sally eilers; december 11, 1908 – january 5, 1978) was an american actress.

Ex Output:
sally eilers


Ex Input:
belstead is a village and civil parish in babergh, suffolk, england.

Ex Output:
belstead


Ex Input:
euclid of alexandria (about 325 bc–265 bc) was a greek mathematician who lived in alexandria, egypt and worked at the library of alexandria.

Ex Output:

euclid