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

Input: Consider Input: Sentence: 'a woman in a red shirt holding a cup of coffee and a donut'. Count the occurrences of the word 'a' in the given sentence.

Output: 4

Input: Consider Input: Sentence: 'a little girl laying on a bed holding a brown teddy bear'. Count the occurrences of the word 'a' in the given sentence.

Output: 3

Input: Consider Input: Sentence: 'blue flowers with green stems next to white flowers in a vase'. Count the occurrences of the word 'flowers' in the given sentence.
Output: 2