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: 'some signs buildings trees bushes a green and white sign'. How many words start with the letter 's' in the sentence.
3

Sentence: 'the inside of a toilet stall on an airplane'. How many words start with the letter 'a' in the sentence.
3

Sentence: 'an expired parking meter with a vehicle in the spot'. How many words start with the letter 'm' in the sentence.

1