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

Ex Input:
Sentence: 'a pizza sitting on top of a pan on top of a table'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:
3


Ex Input:
Sentence: 'a truck and a part of a disabled plane'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:
3


Ex Input:
Sentence: 'a truck and luggage sitting on a cart by the dining saloon car of a train'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:

3