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 boy in a red baseball uniform throws a ball'. How many words start with the letter 'b' in the sentence.
Example Output: 3

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

Example Input: Sentence: 'several baskets of various fruits that are on display'. How many words start with the letter 'o' in the sentence.
Example Output:
2