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

Sentence: 'a colorful photo of a bike against a fence with mountains in the back'. Count the occurrences of the word 'a' in the given sentence.
3

Sentence: 'a dog under a dog bed on a white background'. Count the occurrences of the word 'a' in the given sentence.
3

Sentence: 'a giraffe spitting out water while a gazelle watches in the background'. Count the occurrences of the word 'a' in the given sentence.

2