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 red car near a fire hydrant with multiple hose slots'. How many words start with the letter 'n' in the sentence.
Example Output: 1

Example Input: Sentence: 'someone flying a red kite in a crowded park'. How many words start with the letter 'a' in the sentence.
Example Output: 2

Example Input: Sentence: 'some people are flying kites at the beach'. How many words start with the letter 'a' in the sentence.
Example Output:
2