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 sandwich vegetables and a beer sitting on a table'. How many words start with the letter 'a' in the sentence.
Example Output: 4

Example Input: Sentence: 'a desk with a bunch of laptop and monitors on it'. How many words start with the letter 'w' in the sentence.
Example Output: 1

Example Input: Sentence: 'a person sitting the couch with a laptop in a living room'. How many words start with the letter 'w' in the sentence.
Example Output:
1