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: 'two giraffes are walking down a rocky path'. How many words start with the letter 'a' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a man riding skis down the side of a snow covered ski slope'. How many words start with the letter 's' in the sentence.

Ex Output:
5


Ex Input:
Sentence: 'a kitchen filled with lots of appliances and a counter top'. How many words start with the letter 'a' in the sentence.

Ex Output:

4