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 tennis player swings his racket on a serve'. How many words start with the letter 'o' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'birds are standing in a row on a wooden railing'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a bathroom with exposed pipes and a dirty toilet'. How many words start with the letter 'a' in the sentence.

Ex Output:

3