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

Ex Input:
Sentence: 'a picture of some horses and a person in the street'. How many words contain the letter 'r' in the sentence.

Ex Output:
4


Ex Input:
Sentence: 'an image of a person holding a blunt object is rendered in red and blue tones'. How many words contain the letter 'x' in the sentence.

Ex Output:
0


Ex Input:
Sentence: 'a side mirror of a bus on a street'. How many words contain the letter 's' in the sentence.

Ex Output:

3