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 adults and a child fly a kite at the beach'. How many words start with the letter 'a' in the sentence.

Ex Output:
5


Ex Input:
Sentence: 'the man is standing on a surfboard with a paddle'. How many words start with the letter 's' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a red traffic light sitting on the corner of a street'. How many words start with the letter 'o' in the sentence.

Ex Output:

2