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 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 crowd of people on the street one of which is taking pictures with a cell phone'. How many words start with the letter 'o' in the sentence.
[EX A]: 4

[EX Q]: Sentence: 'a large black bear walking through dried grass'. How many words start with the letter 'w' in the sentence.
[EX A]:
1