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 cat sitting on a pan in an oven'. How many words start with the letter 'a' in the sentence.
Example Output: 3

Example Input: Sentence: 'two men are riding horses on a beach'. How many words start with the letter 'r' in the sentence.
Example Output: 1

Example Input: Sentence: 'the boys holds the bat and the other boy holds the glove'. How many words start with the letter 't' in the sentence.
Example Output:
4