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: 'man in winter clothes riding a snowboard on a gentle slope'. How many words start with the letter 'g' in the sentence.
Example Output: 1

Example Input: Sentence: 'car pass threw a green light in the day light'. How many words start with the letter 'd' in the sentence.
Example Output: 1

Example Input: Sentence: 'here is an asian standing by a yellow fire hydrant'. How many words start with the letter 'h' in the sentence.
Example Output:
2