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 clock tower atop a tall building with a lighting rod'. How many words start with the letter 'a' in the sentence.
Example Output: 4

Example Input: Sentence: 'a clock tower sitting on the side of a walkway'. How many words start with the letter 't' in the sentence.
Example Output: 2

Example Input: Sentence: 'the ball player is sliding in to home plate'. How many words start with the letter 'p' in the sentence.
Example Output:
2