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

Example Input: Sentence: 'a white toilet sitting under a window next to a bath tub'. Count the occurrences of the word 'white' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a child laying on a bed with his head hanging up side down and a teddy bear leaning against the bed'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a small child takes a bite of a donut'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3