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 using a laptop computer on a table'. How many words start with the letter 'a' in the sentence.
[EX A]: 3

[EX Q]: Sentence: 'a zeppelin flying in the air as a water spouts occurs in a city lake'. How many words start with the letter 'a' in the sentence.
[EX A]: 5

[EX Q]: Sentence: 'a yellow bus on street next to a building'. How many words start with the letter 's' in the sentence.
[EX A]:
1