In this task, you need to count the occurrences of the given word in the given sentence.

[EX Q]: Sentence: 'a train is moving on a railroad track through a city'. Count the occurrences of the word 'a' in the given sentence.
[EX A]: 3

[EX Q]: Sentence: 'a large clock mounted to the side of a tall building'. Count the occurrences of the word 'a' in the given sentence.
[EX A]: 2

[EX Q]: Sentence: 'several young men playing a game on the grass near a body of water on a chilly day'. Count the occurrences of the word 'a' in the given sentence.
[EX A]:
3