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

Ex Input:
Sentence: 'the view from the top of a ski slope'. How many words contain the letter 'r' in the sentence.

Ex Output:
1

Ex Input:
Sentence: 'a couple sitting on seats on a train'. How many words contain the letter 'z' in the sentence.

Ex Output:
0

Ex Input:
Sentence: 'a man is playing a physical game in a living room'. How many words contain the letter 'n' in the sentence.

Ex Output:
4