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 crowd of people on the street one of which is taking pictures with a cell phone'. How many words start with the letter 'o' in the sentence.

Ex Output:
4


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: 'a man with luggage awaits to board a small plane'. How many words start with the letter 'a' in the sentence.

Ex Output:

3