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

Ex Input:
Sentence: 'a large red sign on a metal pole'. How many words contain the letter 'q' in the sentence.

Ex Output:
0


Ex Input:
Sentence: 'there are some warning signs on a public toilet'. How many words contain the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a group of men riding skis across snow covered country'. How many words contain the letter 'r' in the sentence.

Ex Output:

5