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

Example Input: Sentence: 'a woman in a red shirt holding a cup of coffee and a donut'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 4

Example Input: Sentence: 'a man tossing a frisbee to another man to catch'. Count the occurrences of the word 'to' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a stuffed animal sitting on a chair in front of a laptop'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3