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

Example Input: Sentence: 'a group of three toilets with a person standing in front of the middle one'. Count the occurrences of the word 'toilets' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a gentleman walking around the edge of a pool as a bus goes by'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a young boy holding a baseball bat next to his head'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
2