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: 'several boxes of glazed donuts on a desk'. How many words start with the letter 'o' in the sentence.
Example Output: 2

Example Input: Sentence: 'a man stands and holds a brown teddy bear'. How many words start with the letter 't' in the sentence.
Example Output: 1

Example Input: Sentence: 'a long rectangular gourmet pizza on a metal tray'. How many words start with the letter 'l' in the sentence.
Example Output:
1