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: 'this is a park with people flying kites'. How many words start with the letter 'p' in the sentence.
Example Output: 2

Example Input: Sentence: 'film production equipment and staff outside the entrance of a building'. How many words start with the letter 'o' in the sentence.
Example Output:
2