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

Example Input: Sentence: 'a group of cows standing next to each other'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a plate of salad on a table containing tuna spinach and carrot'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a man gliding across the water in the surf at the beach'. Count the occurrences of the word 'water' in the given sentence.
Example Output:
1