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: 'people in a field are looking up at a kite'. How many words start with the letter 'u' in the sentence.
Example Output: 1

Example Input: Sentence: 'a man at a restaurant smiling while preparing pizzas'. How many words start with the letter 'p' in the sentence.
Example Output: 2

Example Input: Sentence: 'a building with a balcony and a clock'. How many words start with the letter 'a' in the sentence.
Example Output:
4