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 black and white cat is sitting on the bathroom sink'. How many words start with the letter 'i' in the sentence.
Example Output: 1

Example Input: Sentence: 'a brown dog sitting next to a brown cat on a bed'. How many words start with the letter 'a' in the sentence.
Example Output: 3

Example Input: Sentence: 'a living area with a counter ottoman and mirror'. How many words start with the letter 'c' in the sentence.
Example Output:
1