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 zebra is running toward a shady area under the trees'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a person on a snowboard on a snowy day'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


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

Ex Output:

3