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: 'there are people in chairs watching a projection screen'. How many words start with the letter 't' 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 man is smiling while standing in a city street holding a pastry'. How many words start with the letter 'w' in the sentence.
Example Output:
1