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 very large pizza with pepperoni and olives and someone taking  massive slice'. How many words start with the letter 'l' in the sentence.
Example Output: 1

Example Input: Sentence: 'a person is sitting in the grass on a motorcycle'. How many words start with the letter 'i' in the sentence.
Example Output: 2

Example Input: Sentence: 'a street light some people and a woman wearing a red jacket'. How many words start with the letter 'w' in the sentence.
Example Output:
2