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

Example Input: Sentence: 'a folding table sitting in a kitchen with a window behind the sink'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a man in black shirt playing a game with a nintendo wii controller'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a man on a horse about to go through a jumping course'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3

