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: 'the men are holding on to surfboards outside'. How many words start with the letter 'o' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'a bus and a truck are pictured driving on a street'. How many words start with the letter 'a' in the sentence.

Ex Output:
5


Ex Input:
Sentence: 'an old army tank sits near an old abandoned building'. How many words start with the letter 'a' in the sentence.

Ex Output:

4