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 bus is parked on the side of a road in front of a building'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a bath tub sink and window located in a bathroom'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a street with man cars people and a bus'. How many words start with the letter 'a' in the sentence.

Ex Output:

3