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

Input: Consider Input: Sentence: 'a guy hitting a ball at a professional baseball game'. Count the occurrences of the word 'a' in the given sentence.

Output: 3

Input: Consider Input: Sentence: 'a couple of elephants out in the field having a snack'. Count the occurrences of the word 'a' in the given sentence.

Output: 2

Input: Consider Input: Sentence: 'a turkey sandwich and an apple are on a plate'. Count the occurrences of the word 'an' in the given sentence.
Output: 1