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

[EX Q]: Sentence: 'a baby calf has a tag on its right ear'. Find frequency of the letter 'n'
[EX A]: 1

[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 group of people who are seated together'. Find frequency of the letter 'o'
[EX A]:
5