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

Example Input: Sentence: 'a flat screen tv sitting in the corner of a living room next to a pumpkin'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a red plate and a person is decorating a cake'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a plate with some meat and egg on it'. Count the occurrences of the word 'on' in the given sentence.
Example Output:
1