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 couple of people flying a kite in a field'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a young man in a suit looks down and adjusts his tie'. How many words start with the letter 'a' in the sentence.

Ex Output:
4


Ex Input:
Sentence: 'skiers and snowboarders on a snowy slope near a ski lift'. How many words start with the letter 's' in the sentence.

Ex Output:

5