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: 'an older airplane flies over the country side'. How many words start with the letter 'o' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a horse pulling a carriage with people in the snow'. How many words start with the letter 'a' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a child wearing a yellow hat sitting in the sand on a beach with a yellow kite in the air'. How many words start with the letter 's' in the sentence.

Ex Output:

2