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

Example Input: Sentence: 'a red and a white train cab on a rusty train track'. Count the occurrences of the word 'rusty' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a horse and a dog facing each other in a brown field of grass'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a person sitting on a bed on one side of the wall and a person standing in a bathroom on the other side'. Count the occurrences of the word 'bed' in the given sentence.
Example Output:
1