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 man pulls a rolling suitcase and is wearing a suit'. How many words start with the letter 'a' in the sentence.
Example Output: 4

Example Input: Sentence: 'this is a dish of buttered asparagus with dressing'. How many words start with the letter 'o' in the sentence.
Example Output: 1

Example Input: Sentence: 'a jet with its wheels down is just above the runway'. How many words start with the letter 'j' in the sentence.
Example Output:
2