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 little boy that is sitting down with a phone'. How many words start with the letter 'p' in the sentence.
Example Output: 1

Example Input: Sentence: 'a tall giraffe kissing the bark of a brown tree'. How many words start with the letter 'a' in the sentence.
Example Output: 2

Example Input: Sentence: 'a desk with a cross on it and candles'. How many words start with the letter 'w' in the sentence.
Example Output:
1