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: 'the pigeons are walking around in the park around the benches'. How many words start with the letter 'b' in the sentence.
Example Output: 1

Example Input: Sentence: 'a woman is posing on a floor with a stuffed toy'. How many words start with the letter 'i' in the sentence.
Example Output: 1

Example Input: Sentence: 'a computer on a table with trees and a lake in the background'. How many words start with the letter 'c' in the sentence.
Example Output:
1