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

Ex Input:
Sentence: 'a girl riding a bike wth a dog chasing her'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:
3


Ex Input:
Sentence: 'a train going over a bridge that is over water'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:
2


Ex Input:
Sentence: 'a small pizza on a white plate on a counter'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:

3