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: rsgc1 is a massive young open star cluster in the milky way galaxy.

Output: rsgc1


Input: Consider Input: nickel creek was an american acoustic musical group.

Output: nickel creek


Input: Consider Input: hiromasa yamamoto (山本浩正, yamamoto hiromasa, born 5 june 1979) is a japanese professional athlete.


Output: hiromasa yamamoto