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

Ex Input:
Sentence: 'a man and a woman stand under an umbrella'. How many words contain the letter 's' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'black and white photograph of a man using a cell phone on the street'. How many words contain the letter 'r' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'an open book laid on top of a bed'. How many words contain the letter 't' in the sentence.

Ex Output:

1