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

Example Input: Sentence: 'two adults on skis with a child on skis between them'. Count the occurrences of the word 'on' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a man riding a long surfboard on a wave'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'the table  in the apartment is set for two to have cake and a doll is seated in one chair'. Count the occurrences of the word 'is' in the given sentence.
Example Output:
2