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 train passes over a quiet city park on a bridge'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a man putting a protective covering over a large tv screen'. How many words start with the letter 'l' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'a man holding a glass of orange juice in front of oranges'. How many words start with the letter 'a' in the sentence.

Ex Output:

2