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 shot of the tops of several tall buildings in a city'. How many words start with the letter 'a' in the sentence.
Example Output: 2

Example Input: Sentence: 'a rusty metal park bench in a park'. How many words start with the letter 'a' in the sentence.
Example Output: 2

Example Input: Sentence: 'a woman sits in a restaurant while eating'. How many words start with the letter 'i' in the sentence.
Example Output:
1