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 group of four skiers are getting ready to embark'. How many words start with the letter 'g' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'two asian men standing next to a no smoking sign'. How many words start with the letter 's' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a boat floating on a lake next to a shore filled with buildings'. How many words start with the letter 'n' in the sentence.

Ex Output:

1