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 mother bear and her two young are crossing a shallow river'. How many words start with the letter 'a' in the sentence.

Ex Output:
4


Ex Input:
Sentence: 'a skateboarder is performing a huge jump into the air'. How many words start with the letter 'p' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'many people in a crowd and one is holding up a cellphone'. How many words start with the letter 'u' in the sentence.

Ex Output:

1