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

Example Input: Sentence: 'a kitchen with the tiles of a drop ceiling missing'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a tennis player is waiting to compete on a tennis court'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a police officer on a motorcycle with a sidecar'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3