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: guido altarelli (july 12, 1941 - september 30, 2015) was an italian theoretical physicist.
Example Output: guido altarelli

Example Input: elisabeth charlotte of the palatinate, daughter of france by marriage (27 may 1652 - 8 december 1722) was a german princess and the wife of philippe of france, duke of orléans, younger brother of louis xiv.
Example Output: elisabeth charlotte of the palatinate

Example Input: otters are animals that live near and around water.
Example Output:
otter