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 holding a white frisbee while standing on top of a  beach'. How many words start with the letter 'o' in the sentence.
[EX A]: 2

[EX Q]: Sentence: 'an officer sits on a brown horse on a city street'. How many words start with the letter 'o' in the sentence.
[EX A]: 3

[EX Q]: Sentence: 'a guy wearing a wet suit riding a surfboard'. How many words start with the letter 'a' in the sentence.
[EX A]:
3