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: 'a man holding onto a kite for a woman in the yard'. How many words start with the letter 'o' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'a large jet liner sitting on top of an airport runway'. How many words start with the letter 'a' in the sentence.

Ex Output:

3