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 giraffe is standing behind a stone wall'. How many words start with the letter 'a' in the sentence.
[EX A]: 2

[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: 'woman crossing a city street behind a commercial bus'. How many words start with the letter 'a' in the sentence.
[EX A]:
2