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 brown and white cat laying on blanket on door of open oven'. How many words start with the letter 'o' in the sentence.

Ex Output:
5


Ex Input:
Sentence: 'a man and three children playing with a kite on the grass and other people riding bikes on a nearby road'. How many words start with the letter 'a' in the sentence.

Ex Output:
5


Ex Input:
Sentence: 'a dinning area with table chairs and a refrigerator'. How many words start with the letter 'a' in the sentence.

Ex Output:

4