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 Q]: Sentence: 'a person takes a picture of a reflection in a mirror in the dark'. How many words start with the letter 'p' in the sentence.
[EX A]: 2

[EX Q]: Sentence: 'a young man wearing glasses with a tooth brush in his mouth'. How many words start with the letter 'b' in the sentence.
[EX A]: 1

[EX Q]: Sentence: 'a person with a life vest riding a speed boat'. How many words start with the letter 's' in the sentence.
[EX A]:
1