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

[Q]: Sentence: 'this is a yellow train riding the rails'. How many words contain the letter 'n' in the sentence.
[A]: 2


[Q]: Sentence: 'a fire hydrant on a neighborhood street with trees and shrubs around it'. How many words contain the letter 'k' in the sentence.
[A]: 0


[Q]: Sentence: 'some people are on some grass flying kites'. How many words contain the letter 'r' in the sentence.
[A]:
2