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: 'a hotdog with onions on it is sitting on tinfoil'. How many words start with the letter 'o' in the sentence.
Example Output: 3

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: 'a room with a bunch of furniture in it'. How many words start with the letter 'i' in the sentence.
Example Output:
2