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

Ex Input:
Sentence: 'a small child sitting in a seat with a bag'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:
3


Ex Input:
Sentence: 'a horse out in a grassy green field'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:
2


Ex Input:
Sentence: 'four sheep walking up a a steep mountain trail'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:

2