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: 'two men are flying kites in a field in front of a parking lot'. How many words start with the letter 'f' in the sentence.
Example Output: 3

Example Input: Sentence: 'a person in a body of water with a surf board'. How many words start with the letter 'b' in the sentence.
Example Output: 2

Example Input: Sentence: 'a toilet painted like a cow sitting next to a sink painted like a cow in a restroom'. How many words start with the letter 'p' in the sentence.
Example Output:
2