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

Example Input: Sentence: 'a bird is standing on the edge of a book'. How many words contain the letter 'o' in the sentence.
Example Output: 3

Example Input: Sentence: 'a man herding brown colored animals with a dog'. How many words contain the letter 'z' in the sentence.
Example Output: 0

Example Input: Sentence: 'train stopped at station with doors open waiting for passengers'. How many words contain the letter 'e' in the sentence.
Example Output:
3