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

Ex Input:
Sentence: 'a woman in a wheelchair is about to play tennis'. How many words contain the letter 'r' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'a group of people standing together talking '. How many words contain the letter 'b' in the sentence.

Ex Output:
0


Ex Input:
Sentence: 'an orange cat napping on top of a kitty tree'. How many words contain the letter 'r' in the sentence.

Ex Output:

2