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 male skateboarder in a black shirt doing a trick'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a pole with two traffic signs on it in the daytime'. How many words start with the letter 't' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'an airplane is parked on a runway with a setting sun in the background'. How many words start with the letter 'b' in the sentence.

Ex Output:

1