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

Input: Consider Input: Sentence: 'a apple that is sitting on top of a knife'. How many words contain the letter 'u' in the sentence.

Output: 0

Input: Consider Input: Sentence: 'the view from the top of a ski slope'. How many words contain the letter 'r' in the sentence.

Output: 1

Input: Consider Input: Sentence: 'a young boy swinging a baseball bat during a baseball game'. How many words contain the letter 'o' in the sentence.
Output: 2