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 man that has a tennis racket by a court'. How many words start with the letter 'h' in the sentence.
Example Output: 1

Example Input: Sentence: 'a guy looks at a tablet and holds his skateboard while riding public transportation'. How many words start with the letter 'l' in the sentence.
Example Output: 1

Example Input: Sentence: 'a green bus driving down the street'. How many words start with the letter 'd' in the sentence.
Example Output:
2