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 bathroom with a toilet with a blue seat'. How many words start with the letter 'b' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'many colorful umbrellas hang over a colorful street'. How many words start with the letter 'm' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'an infant touching the keys of a computer keyboard'. How many words start with the letter 'a' in the sentence.

Ex Output:

2