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

Input: Consider Input: Sentence: 'a person showing a selfie of themself to the camera'. Count the occurrences of the word 'a' in the given sentence.

Output: 2

Input: Consider Input: Sentence: 'a small child laying in a bed next to a shelf'. Count the occurrences of the word 'a' in the given sentence.

Output: 3

Input: Consider Input: Sentence: 'flour people on a corner all using their cell phones'. Count the occurrences of the word 'on' in the given sentence.
Output: 1