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

Input: Consider Input: Sentence: 'a woman and a cat are sitting at a laptop'. Count the occurrences of the word 'a' in the given sentence.

Output: 3


Input: Consider Input: Sentence: 'a small train engine pulling a freight car'. Count the occurrences of the word 'a' in the given sentence.

Output: 2


Input: Consider Input: Sentence: 'a man has built a robot out of a cell phone'. Count the occurrences of the word 'a' in the given sentence.


Output: 3