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 person on skis goes across a snowy slope'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a group of giraffes faces and stare in the same direction while one of the faces and stares in the other '. How many words start with the letter 'o' in the sentence.

Ex Output:
4


Ex Input:
Sentence: 'a striped bus travels down a city street at night'. How many words start with the letter 'a' in the sentence.

Ex Output:

3