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

Ex Input:
Sentence: 'a man riding a skateboard on a bench near some trees'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:
3


Ex Input:
Sentence: 'a small train engine pulling a freight car'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:
2


Ex Input:
Sentence: 'a man hitting a tennis ball with a racquet on a court'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:

4