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

Example Input: Sentence: 'a man riding skis on a snow covered ski slope'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a plate filled with various food items and a carton of milk'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'the gray and white cart is looking toward an image of a cat on the screen'. Count the occurrences of the word 'the' in the given sentence.
Example Output:
2