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 man riding skis down the side of a snow covered ski slope'. How many words start with the letter 's' in the sentence.

Ex Output:
5


Ex Input:
Sentence: 'a bathroom that has a toilet and window in it'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a pile of stuffed animals with a do not touch sign on top'. How many words start with the letter 'w' in the sentence.

Ex Output:

1