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: plumbaginaceae is a family of flowering plants are about 560 species in 10 genera found all over the world.
Example Output: plumbaginaceae

Example Input: maicon douglas sisenando (born 26 july 1981) is a brazilian football player.
Example Output: maicon douglas sisenando

Example Input: evgeny platov (born august 7, 1967, odessa, ukraine).
Example Output:
evgeny platov