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:
ash ketchum (satoshi in japanese) is a character from the "pokémon" anime.

Ex Output:
ash ketchum


Ex Input:
anton buttigieg, kuom ( ]; 19 february 1912 – 5 may 1983) was a maltese politician.

Ex Output:
anton buttigieg


Ex Input:
a pie chart is a type of chart with the shape of a pie or circle.

Ex Output:

pie chart