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 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 woman wearing gloves that has a kite'. How many words start with the letter 't' in the sentence.
Example Output: 1

Example Input: Sentence: 'a sign indicating the location as castle rising castle'. How many words start with the letter 'l' in the sentence.
Example Output:
1