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.

[Q]: Sentence: 'a man in vest and tie holding a cellphone'. How many words start with the letter 'a' in the sentence.
[A]: 3


[Q]: Sentence: 'a man without a shirt riding a skateboard'. How many words start with the letter 'r' in the sentence.
[A]: 1


[Q]: Sentence: 'a toilet a sink a bottle soap cup and a mirror'. How many words start with the letter 'a' in the sentence.
[A]:
5