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 police car driving by a construction truck'. How many words start with the letter 'b' in the sentence.
[EX A]: 1

[EX Q]: Sentence: 'a picture of a zebra that is walking in the grass'. How many words start with the letter 'z' in the sentence.
[EX A]: 1

[EX Q]: Sentence: 'a group of friends loitering on a street island in a city'. How many words start with the letter 'o' in the sentence.
[EX A]:
2