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 men on motorcycles and wearing helmets'. How many words start with the letter 'w' in the sentence.
Example Output: 1

Example Input: Sentence: 'a street sign view in a very blurry picture'. How many words start with the letter 's' in the sentence.
Example Output: 2

Example Input: Sentence: 'person holding up a small orange and white electronic device'. How many words start with the letter 'a' in the sentence.
Example Output:
2