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

Example Input: Sentence: 'a group of people standing outside in a park eating food on paper plates'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'four giraffes stand around the grassy area of a corral'. Count the occurrences of the word 'giraffes' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a cat with a pensive look guarding its plate by a computer'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3