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 group of parked bikes sitting on the side of a road'. How many words start with the letter 'o' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a ladder sitting up against a red wall in a room'. How many words start with the letter 'a' in the sentence.

Ex Output:
4


Ex Input:
Sentence: 'a room with three beds and luggage on the floor and a backpack on one of the beds'. How many words start with the letter 'b' in the sentence.

Ex Output:

3