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

Example Input: Sentence: 'a bathroom with towels hanging next to a window'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a road sign on a corner in the snow'. Count the occurrences of the word 'in' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a large knife lies on a plate containing half of a chocolate cake'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3