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

Ex Input:
Sentence: 'a bird is standing on the edge of a book'. How many words contain the letter 'o' in the sentence.

Ex Output:
3

Ex Input:
Sentence: 'people standing in a river surrounding an elephant some are touching it'. How many words contain the letter 'd' in the sentence.

Ex Output:
2

Ex Input:
Sentence: 'a woman holding a knife is cutting a cake'. How many words contain the letter 'v' in the sentence.

Ex Output:
0