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

Input: Consider Input: Sentence: 'a man is looking slyly at the camera while sitting at his laptop at a desk'. Count the occurrences of the word 'at' in the given sentence.

Output: 3

Input: Consider Input: Sentence: 'a woman cutting cake while another woman is holding a plate'. Count the occurrences of the word 'a' in the given sentence.

Output: 2

Input: Consider Input: Sentence: 'a train coming into a train station in an urban area'. Count the occurrences of the word 'a' in the given sentence.
Output: 2