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

Example Input: Sentence: 'a couple of zebras are standing in a pin'. How many words contain the letter 'a' in the sentence.
Example Output: 5

Example Input: Sentence: 'a large airplane flying over a dry grass hillside'. How many words contain the letter 'e' in the sentence.
Example Output: 4

Example Input: Sentence: 'a picture of a car parked in a parking lot'. How many words contain the letter 'u' in the sentence.
Example Output:
1