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

Ex Input:
Sentence: 'person standing in the grass striking a baseball with a bat'. How many words contain the letter 's' in the sentence.

Ex Output:
5


Ex Input:
Sentence: 'the zebra is showing his rear end to the camera'. How many words contain the letter 'r' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a man walking through a lobby of a mall'. How many words contain the letter 'r' in the sentence.

Ex Output:

1