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 picture of a very clean bed in the room'. How many words start with the letter 'r' in the sentence.
1

Sentence: 'an older airplane flying above buildings and fields'. How many words start with the letter 'a' in the sentence.
4

Sentence: 'a passenger train that is passing under some blue bars'. How many words start with the letter 'u' in the sentence.

1