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 passanger train is coming down the tracks'. How many words start with the letter 't' in the sentence.
Example Output: 3

Example Input: Sentence: 'a pitcher throwing a baseball during a baseball game'. How many words start with the letter 'b' in the sentence.
Example Output: 2

Example Input: Sentence: 'a couple of baseball players standing on a field near a base'. How many words start with the letter 's' in the sentence.
Example Output:
1