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.

Example Input: Sentence: 'two and a half hotdogs on paper plates are on a counter'. How many words start with the letter 'p' in the sentence.
Example Output: 2

Example Input: Sentence: 'railway train passenger cars with graffiti parked on a gravel lot'. How many words start with the letter 'l' in the sentence.
Example Output: 1

Example Input: Sentence: 'a boy training on a snow board with snow covered slopes in backdrop'. How many words start with the letter 'b' in the sentence.
Example Output:
3