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

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 elephant that is eating some leaves from a tree'. How many words contain the letter 'n' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a little girl in front of a book shelf and chair'. How many words contain the letter 'y' in the sentence.

Ex Output:

0