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 man at a restaurant smiling while preparing pizzas'. How many words start with the letter 'p' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a boy is biting into a piece of pizza'. How many words start with the letter 'b' in the sentence.

Ex Output:

2