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: 'three motorcycle police in front of a crowd attending an outdoor summer event with beer truck behind them'. How many words start with the letter 'p' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'a lady playing a game of tennis on a green and blue court'. How many words start with the letter 'l' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'trains parked on rail road tracks next to a tractor'. How many words start with the letter 'r' in the sentence.

Ex Output:

2