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: 'group of zebras and gazelles grazing on the grass'. How many words start with the letter 'g' in the sentence.
Example Output: 4

Example Input: Sentence: 'a man wearing a striped tie and a jacket'. How many words start with the letter 'j' in the sentence.
Example Output: 1

Example Input: Sentence: 'a full plate full of delicious food sets on top of the table'. How many words start with the letter 'd' in the sentence.
Example Output:
1