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

Example Input: Sentence: 'a train on a train track next to a concrete platform'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a bed room with a large window and a neatly made bed'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a group of cows walking back out of the water'. Count the occurrences of the word 'of' in the given sentence.
Example Output:
2