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

Example Input: Sentence: 'a woman pushing the stroller is walking down the street'. Count the occurrences of the word 'the' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a woman with a walker is sitting on a park bench'. Count the occurrences of the word 'with' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a picture of a tower clock in the middle of the city on top of a building'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3