In this task, you need to count the number of words in a sentence that start with the given letter. Answer with numbers and not words.

Input: Consider Input: Sentence: 'a girl and her dog walk past a bike'. How many words start with the letter 'a' in the sentence.

Output: 3


Input: Consider Input: Sentence: 'a person walking on a city street with a luggage bag'. How many words start with the letter 'w' in the sentence.

Output: 2


Input: Consider Input: Sentence: 'a large crowd of people are on the ski mountain'. How many words start with the letter 's' in the sentence.


Output: 1