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

Example Input: Sentence: 'there are some warning signs on a public toilet'. How many words contain the letter 'a' in the sentence.
Example Output: 3

Example Input: Sentence: 'a small child next to a bunch of bananas and an orange'. How many words contain the letter 'p' in the sentence.
Example Output: 0

Example Input: Sentence: 'snow skiers with backpacks in high altitude mountain area'. How many words contain the letter 'z' in the sentence.
Example Output:
0