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

Input: Consider Input: Sentence: 'a person that is flying a hamburger kite'. How many words contain the letter 'b' in the sentence.

Output: 1


Input: Consider Input: Sentence: 'the train needs to be serviced so it is o the truck'. How many words contain the letter 'n' in the sentence.

Output: 2


Input: Consider Input: Sentence: 'a snowboarder at the top of the slope in front of a chairlift'. How many words contain the letter 'a' in the sentence.


Output: 5