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

Example Input: Sentence: 'a furry dog standing next to a fire hydrant'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'there are some chairs under an umbrella at the beach'. Count the occurrences of the word 'at' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a bunch of octopus kites flying in the air and a crowd of people standing around watching from a white tent and a yellow one'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
4