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

Example Input: Sentence: 'a man sitting in front of a laptop while a standing man looks at the screen'. Count the occurrences of the word 'front' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a woman holds a furry dog by its leash'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a thin man slouches on a bench while holding an umbrella'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
2