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

Input: Consider Input: Sentence: 'a green blue and yellow boat sitting in a harbor'. How many words contain the letter 'o' in the sentence.

Output: 3


Input: Consider Input: Sentence: 'a clock tower next to a building in a city'. How many words contain the letter 'a' in the sentence.

Output: 3


Input: Consider Input: Sentence: 'the front of a chinese postal store with people walking by'. How many words contain the letter 'n' in the sentence.


Output: 3