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

Example Input: Sentence: 'a yellow sign warns of a plank surface in front of a large gray building'. Count the occurrences of the word 'yellow' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a bucket is sitting on the floor of a bathroom'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a bow with a toothbrush in it on the counter'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
2