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 woman walking up to a double decker bus that has stopped'. How many words start with the letter 'w' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'person surfing in the sea on the surfboard'. How many words start with the letter 's' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a herd of elephants walking across a river'. How many words start with the letter 'a' in the sentence.

Ex Output:

3