TASK DEFINITION: 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.
PROBLEM: Zvonimir Djurkinjak and Stasa Poznanovic were the best mixed double at the 2011 Croatian International.

SOLUTION: 2011

PROBLEM: The active ingredient of Eribulin Mesylate (E7389) is a type of Macrolide

SOLUTION: Eribulin Mesylate (E7389)

PROBLEM: 2011–12 Costa Rican Primera División season,CS Herediano lived in Heredia

SOLUTION:
CS Herediano