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 man pulls a rolling suitcase and is wearing a suit'. How many words start with the letter 'a' in the sentence.
[EX A]: 4

[EX Q]: Sentence: 'kids at a skateboard park riding skateboards and watching'. How many words start with the letter 'a' in the sentence.
[EX A]: 3

[EX Q]: Sentence: 'some signs and the roof of a train station'. How many words start with the letter 'a' in the sentence.
[EX A]:
2