In this task, you need to count the number of times the given letter appears in the given sentence.

Ex Input:
Sentence: 'a batter, catcher and umpire waiting for the pitch and a major league baseball game'. Find frequency of the letter 'c'

Ex Output:
3


Ex Input:
Sentence: 'a  woman standing next to a man on a motorcycle in front of a market'. Find frequency of the letter 'l'

Ex Output:
1


Ex Input:
Sentence: 'a white plate topped with squid, greens and oranges'. Find frequency of the letter 'p'

Ex Output:

3