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 striped bus travels down a city street at night'. How many words start with the letter 'a' in the sentence.
Example Output: 3

Example Input: Sentence: 'the colorful fruit is laid out in boxes'. How many words start with the letter 'i' in the sentence.
Example Output: 2

Example Input: Sentence: 'there is a lot of foot traffic going down broadway'. How many words start with the letter 'a' in the sentence.
Example Output:
1