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

Example Input: Sentence: 'a tall plant protrudes from a glass vase'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'the soldier on horseback statue stands guard over the citys residences and buildings'. Count the occurrences of the word 'the' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a picture of a dark figure looking at a tooth brush'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3