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 colorful kite flies over top a house'. How many words start with the letter 'f' in the sentence.
Example Output: 1

Example Input: Sentence: 'a woman walks in the street in the rain'. How many words start with the letter 'i' in the sentence.
Example Output: 2

Example Input: Sentence: 'a large passenger jet flying through a blue sky'. How many words start with the letter 'l' in the sentence.
Example Output:
1