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 couple of people are riding horses in a village'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'the men are holding on to surfboards outside'. How many words start with the letter 'o' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a man in plaid shirt doing a trick on skateboard'. How many words start with the letter 'd' in the sentence.

Ex Output:

1