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 fighter jet on a runway with a cover over the cockpit'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a husky is sleeping while wearing a green bandana'. How many words start with the letter 's' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'a person riding a wave on top of a surfboard'. How many words start with the letter 'o' in the sentence.

Ex Output:

2