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 man using a laptop computer on a table'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a man is sitting on his motorcycle outside'. How many words start with the letter 'o' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a stack of several sandwiches on top of each other'. How many words start with the letter 's' in the sentence.

Ex Output:

3