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.

Sentence: 'a lit clock mounted on the side of a red building at night'. How many words start with the letter 'a' in the sentence.
3

Sentence: 'several boxes of glazed donuts on a desk'. How many words start with the letter 'o' in the sentence.
2

Sentence: 'a man in the desert is riding a horse'. How many words start with the letter 'i' in the sentence.

2