In this task, you need to count the number of words in a sentence that contain the given letter

Ex Input:
Sentence: 'a biscuit that someone has taken a bite out of'. How many words contain the letter 'k' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'young girls with backpacks are standing near stairs that look to go to the subway'. How many words contain the letter 'r' in the sentence.

Ex Output:
4


Ex Input:
Sentence: 'a couple of surfers are walking out of the sea'. How many words contain the letter 's' in the sentence.

Ex Output:

2