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: 'people on a tour bus with half the top cut off'. How many words start with the letter 'b' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'a man pulls a rolling suitcase and is wearing a suit'. How many words start with the letter 'a' in the sentence.

Ex Output:
4


Ex Input:
Sentence: 'a water skier holds a rope as he rides a wave'. How many words start with the letter 'w' in the sentence.

Ex Output:

2