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 pizzas sitting on top of a pan on a counter'. How many words start with the letter 'p' in the sentence.
Example Output: 2

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: 'cars are driving through a green traffic light'. How many words start with the letter 'c' in the sentence.
Example Output:
1