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.

[Q]: Sentence: 'a person sitting on a stone wall using a cellular phone'. How many words start with the letter 's' in the sentence.
[A]: 2


[Q]: Sentence: 'some very pretty giraffes standing by a big fence'. How many words start with the letter 'f' in the sentence.
[A]: 1


[Q]: Sentence: 'two people are caryiing their surf boards while walking on a beach'. How many words start with the letter 'o' in the sentence.
[A]:
1