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: 'on one plate there is glazed donut and on the other plate there is mug of hot chocolate with a leaf shape swirled in it'. How many words start with the letter 's' in the sentence.
Example Output: 2

Example Input: Sentence: 'a man putting a protective covering over a large tv screen'. How many words start with the letter 'l' in the sentence.
Example Output: 1

Example Input: Sentence: 'a dog and a goat with their noses touching at fence'. How many words start with the letter 'g' in the sentence.
Example Output:
1