TASK DEFINITION: In this task, you need to count the occurrences of the given word in the given sentence.
PROBLEM: Sentence: 'a person is riding a bicycle but there is a train in the background'. Count the occurrences of the word 'a' in the given sentence.

SOLUTION: 3

PROBLEM: Sentence: 'a black bird sitting on a wall next to grass'. Count the occurrences of the word 'next' in the given sentence.

SOLUTION: 1

PROBLEM: Sentence: 'a couple of people standing in a field flying a kite'. Count the occurrences of the word 'a' in the given sentence.

SOLUTION:
3