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.

Ex Input:
Sentence: 'a bathroom mirror reflecting a sink and bathtub'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a blue bench a house and some bushes'. How many words start with the letter 'b' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a cat sitting next to boxes of produce sitting in front of a store'. How many words start with the letter 's' in the sentence.

Ex Output:

3