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

Example Input: Sentence: 'a clock tower next to a building in a city'. How many words contain the letter 'a' in the sentence.
Example Output: 3

Example Input: Sentence: 'a stop sign that has been spray painted'. How many words contain the letter 'o' in the sentence.
Example Output: 1

Example Input: Sentence: 'small pastry on white plate with marshmallow topping'. How many words contain the letter 'z' in the sentence.
Example Output:
0