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

Example Input: Sentence: 'a brown dog sitting in front of a tv in a room'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a girl in blue shit and shorts holding a frisbee in grassy area'. Count the occurrences of the word 'in' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a train engine going down a track next to a bare patch of ground'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3