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

Example Input: Sentence: 'a girl in blue shit and shorts holding a frisbee in grassy area'. Count the occurrences of the word 'in' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a man riding skis down a snow covered slope'. Count the occurrences of the word 'snow' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a man is taking a big bite out of a hot dog'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3