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 bus is parked on the side of a road in front of a building'. How many words start with the letter 'a' in the sentence.
Example Output: 3

Example Input: Sentence: 'a little boy that is sitting down with a phone'. How many words start with the letter 'p' in the sentence.
Example Output: 1

Example Input: Sentence: 'a red bench in the middle of a city street'. How many words start with the letter 't' in the sentence.
Example Output:
1