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 silver blue and red jet is flying over a fence'. How many words start with the letter 'f' in the sentence.
Example Output: 2

Example Input: Sentence: 'a large clock that is in the middle of the forest'. How many words start with the letter 't' in the sentence.
Example Output: 3

Example Input: Sentence: 'a white plate has meat mashed potatoes and carrots on it'. How many words start with the letter 'p' in the sentence.
Example Output:
2