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

Example Input: Sentence: 'a line of portable toilets stands outdoors under trees'. How many words contain the letter 'l' in the sentence.
Example Output: 3

Example Input: Sentence: 'a cat that is laying down with a mouse on top of it'. How many words contain the letter 'm' in the sentence.
Example Output: 1

Example Input: Sentence: 'there is a girl that is standing smiling holding a hot dog'. How many words contain the letter 'm' in the sentence.
Example Output:
1