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 soccer player running and kicking a soccer ball during a match'. How many words start with the letter 'a' in the sentence.

Ex Output:
4


Ex Input:
Sentence: 'people walking down the street while some people ride their bicycles'. How many words start with the letter 'w' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'these snowboards are on the slope of a mountain'. How many words start with the letter 'o' in the sentence.

Ex Output:

2