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

Example Input: Sentence: 'a couple of zebras are standing in a pin'. How many words contain the letter 'a' in the sentence.
Example Output: 5

Example Input: Sentence: 'a man with a surfboard walking across a bridge towards the ocean'. How many words contain the letter 'w' in the sentence.
Example Output: 3

Example Input: Sentence: 'a leafy green plant grown outside close to the ground'. How many words contain the letter 'y' in the sentence.
Example Output:
1