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

Example Input: Sentence: 'a red truck hauling a truck behind it on a highway'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a bed room with a large window and a neatly made bed'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a female in a blue top is sitting on a white chair'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3