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

Example Input: Sentence: 'a truck and a part of a disabled plane'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a woman laying in a bed with messy hair'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a person feeding a cow with a bottle'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3