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

Example Input: Sentence: 'a group of bears sitting next to each other on a sidewalk'. How many words contain the letter 't' in the sentence.
Example Output: 4

Example Input: Sentence: 'a dog jumping up and catching a frisbee in its mouth'. How many words contain the letter 'r' in the sentence.
Example Output: 1

Example Input: Sentence: 'a train station with a blue train at the station'. How many words contain the letter 'r' in the sentence.
Example Output:
2