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 boy waves at the camera standing on a tree stump'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'some black birds sitting on some rocks and some water'. How many words start with the letter 'b' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a person standing outside in a street with a scarf around there neck'. How many words start with the letter 'i' in the sentence.

Ex Output:

1


