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: 'there is a lap top on a desk at a office'. How many words start with the letter 'o' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a stop sign and a no stopping sign are on a street corner'. How many words start with the letter 's' in the sentence.

Ex Output:
5


Ex Input:
Sentence: 'a herd of cows traveling down the street'. How many words start with the letter 't' in the sentence.

Ex Output:

2