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 couples sit on a bench in front of bushes with pink flowers'. How many words start with the letter 'o' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a young girl wearing a pink tie and glasses'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a woman sitting back on a couch holding a little white dog'. How many words start with the letter 's' in the sentence.

Ex Output:

1