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 group of four people are riding a ski lift as they ride over the snowy mountain'. How many words start with the letter 'a' in the sentence.
[EX A]: 4

[EX Q]: Sentence: 'several people are playing frisbee in a park'. How many words start with the letter 'a' in the sentence.
[EX A]: 2

[EX Q]: Sentence: 'a blue and white train is coming down some tracks'. How many words start with the letter 'c' in the sentence.
[EX A]:
1