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

Example Input: Sentence: 'several young men playing a game on the grass near a body of water on a chilly day'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'real to life dummy stuffed into a suitcase'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a man riding a snow board off the side of a building'. Count the occurrences of the word 'of' in the given sentence.
Example Output:
1