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 terrier in a black and light brown far next to each other'. How many words start with the letter 'b' in the sentence.
Example Output: 2

Example Input: Sentence: 'a group of giraffes faces and stare in the same direction while one of the faces and stares in the other '. How many words start with the letter 'o' in the sentence.
Example Output: 4

Example Input: Sentence: 'a woman and a younger boy preparing food in a kitchen'. How many words start with the letter 'a' in the sentence.
Example Output:
4