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: The "Associazione Sportiva Roma S.p.A." is the non-abbreviated name of A.S. Roma.
Example Output: A.S. Roma

Example Input: Monocacy National Battlefield is located in Frederick County, Maryland.
Example Output: Monocacy National Battlefield

Example Input: Comet 13P/Olbers's orbital period (years) is 69.52.
Example Output:
13P/Olbers