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

Ex Input:
Sentence: 'a woman is posing next to a stop sign'. How many words contain the letter 'u' in the sentence.

Ex Output:
0


Ex Input:
Sentence: 'a carrot and celery are on a cutting board'. How many words contain the letter 's' in the sentence.

Ex Output:
0


Ex Input:
Sentence: 'they have been having fun at the backyard barbeque'. How many words contain the letter 'k' in the sentence.

Ex Output:

1