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

Example Input: Sentence: 'several people and a dog riding on a small boat'. How many words contain the letter 'l' in the sentence.
Example Output: 3

Example Input: Sentence: 'a blue traffic sign next to a parked car on a city street'. How many words contain the letter 'g' in the sentence.
Example Output: 1

Example Input: Sentence: 'the luggage area at the virgin american airport'. How many words contain the letter 'r' in the sentence.
Example Output:
4