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 fire truck and an ambulance driving down the street'. How many words start with the letter 'a' in the sentence.
Example Output: 4

Example Input: Sentence: 'a man in a wheel chair holding a tennis racquet'. How many words start with the letter 't' in the sentence.
Example Output: 1

Example Input: Sentence: 'an orange concoction comes together in a blender'. How many words start with the letter 'c' in the sentence.
Example Output:
2