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

Ex Input:
Sentence: 'a man with a long grey beard in a white shirt and green tie at a pub full of greenshirted patrons'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:
4


Ex Input:
Sentence: 'a small child laying in a bed next to a shelf'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:
3


Ex Input:
Sentence: 'a room with a small light in the middle with a computer'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:

3