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

Ex Input:
Sentence: 'a boat carries a smaller motorboat that is hitched on the back'. Count the occurrences of the word 'a' in the given sentence.

Ex Output:
2


Ex 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.

Ex Output:
3


Ex Input:
Sentence: 'several young men playing a game on the grass near a body of water on a chilly day'. Count the occurrences of the word 'on' in the given sentence.

Ex Output:

2