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

Ex Input:
Sentence: 'a pig in a make shift shelter being watched by a cat'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:
3


Ex Input:
Sentence: 'black and white photo of a person with an umbrella on a dock'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:
2


Ex Input:
Sentence: 'an old stone wall with a large tower on top'. Count the occurrences of the word 'an' in the given sentence.

Ex Output:

1