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

[EX Q]: Sentence: 'a group of people having dinner and drinking wine'. Find frequency of the letter 'r'
[EX A]: 3

[EX Q]: Sentence: 'a snowboarder making a jump of a snowy ledge'. Find frequency of the letter 'o'
[EX A]: 4

[EX Q]: Sentence: 'a batter, catcher and umpire during a baseball game'. Find frequency of the letter 'r'
[EX A]:
4