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 yellow grey and white bird on a small group of twigs'. How many words start with the letter 'b' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'a tennis player walking off the court'. How many words start with the letter 't' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a dog in a cage looking out of the cage'. How many words start with the letter 'o' in the sentence.

Ex Output:

2