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.

Ex Input:
Sentence: 'a baseball player prepares to swing at a pitch'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a baseball player swinging a bat while a catcher is behind him with his mitt out'. How many words start with the letter 'w' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a tennis player standing on a tennis court looking up at the sky'. How many words start with the letter 'a' in the sentence.

Ex Output:

3