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: 'woman wearing all black holding up a white surfboard'. Count the occurrences of the word 'holding' in the given sentence.
Example Output: 1

Example Input: Sentence: 'the clouds rolling in over a few houses'. Count the occurrences of the word 'houses' in the given sentence.
Example Output:
1