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

Ex Input:
Sentence: 'an elephant standing on a green grass area'. How many words contain the letter 'm' in the sentence.

Ex Output:
0


Ex Input:
Sentence: 'street signs are affixed to a utility pole'. How many words contain the letter 'u' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'people partaking of various activities while at the beach'. How many words contain the letter 'r' in the sentence.

Ex Output:

2