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

Example Input: Sentence: 'a man that is sitting on a horse in the grass'. How many words contain the letter 'y' in the sentence.
Example Output: 0

Example Input: Sentence: 'a dog on a deck ripping in to a plastic frisbee'. How many words contain the letter 'l' in the sentence.
Example Output: 1

Example Input: Sentence: 'a couple of photos of a group of people playing with interactive a gaming unit'. How many words contain the letter 'r' in the sentence.
Example Output:
2