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

Example Input: Sentence: 'a woman is riding a wave on a surfboard'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a tall plant protrudes from a glass vase'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a man laying on top of an orange raft'. Count the occurrences of the word 'orange' in the given sentence.
Example Output:
1