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

Input: Consider Input: Sentence: 'a pizza pie is on a wooden serving tray'. How many words contain the letter 's' in the sentence.

Output: 2


Input: Consider Input: Sentence: 'a green and white street sign on a pole and a light'. How many words contain the letter 's' in the sentence.

Output: 2


Input: Consider Input: Sentence: 'a train pulling into a train station while its raining'. How many words contain the letter 'n' in the sentence.


Output: 6