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

Example Input: Sentence: 'a big shaggy dog is tied up with its leash next to some stairs outside of a building'. Count the occurrences of the word 'shaggy' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a group of fire trucks ride down the road'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 1

Example Input: Sentence: 'the orange and white fire hydrant sits on the edge of the street'. Count the occurrences of the word 'the' in the given sentence.
Example Output:
3