This task is about identifying the subject of a given sentence. The subject of a sentence is the person, place, or thing that is performing the action of the sentence. The subject represents what or whom the sentence is about. Each sentence in this task is guaranteed to contain a single subject. The input is a sentence and the output is the identified subject of that sentence.

Example Input: Jack Kirby is an American.
Example Output: Jack Kirby

Example Input: The largest city in Turkey is Istanbul.
Example Output: Turkey

Example Input: Halimah Yacob is a leader of Singapore.
Example Output:
Singapore