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

Ex Input:
Sentence: 'a small terrier stands in the open suitcase ready to go'. How many words contain the letter 'l' in the sentence.

Ex Output:
1

Ex Input:
Sentence: 'a man in a helmet leans on his motorcycle'. How many words contain the letter 'n' in the sentence.

Ex Output:
4

Ex Input:
Sentence: 'a bicycle with helmet parked inside a house'. How many words contain the letter 'k' in the sentence.

Ex Output:
1