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

Example Input: Sentence: 'a group of people in a field flying kites on a clear day'. 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: 'two cats are walking on wood near a trash can'. Count the occurrences of the word 'are' in the given sentence.
Example Output:
1