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

Example Input: Sentence: 'a pizza is on a cooling rack on a counter'. Count the occurrences of the word 'on' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a boy is playing video games in a dated living room'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a sign in a city street that says smile between the hours of 5pm and 9am'. Count the occurrences of the word '5pm' in the given sentence.
Example Output:
1