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 young woman is picking a black cat up off of the floor'. How many words start with the letter 'a' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a green place mat sitting on a table with a couple of plates of food and a drink placed upon it'. How many words start with the letter 'p' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a brown and white truck sitting in the back of a flat bed'. How many words start with the letter 'b' in the sentence.

Ex Output:

3