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 person on a snowboard on a snowy day'. How many words start with the letter 'a' in the sentence.

Ex Output:
3


Ex Input:
Sentence: 'a fire truck and an ambulance driving down the street'. How many words start with the letter 'a' in the sentence.

Ex Output:
4


Ex Input:
Sentence: 'a mug is next to a doughnut on a table'. How many words start with the letter 't' in the sentence.

Ex Output:

2