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 closeup picture of a polar bears head'. How many words start with the letter 'a' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'dude in shades sits and eats a hotdog'. How many words start with the letter 's' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a pigeon balances precariously at the highest point of the tower'. How many words start with the letter 'a' in the sentence.

Ex Output:

2