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 cat standing on a suitcase and checking out peoples bags'. How many words start with the letter 's' in the sentence.
[EX A]: 2

[EX Q]: Sentence: 'a picture of a mirror on a bike'. How many words start with the letter 'o' in the sentence.
[EX A]: 2

[EX Q]: Sentence: 'person surfing in the sea on the surfboard'. How many words start with the letter 's' in the sentence.
[EX A]:
3