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

[Q]: Sentence: 'a piece of meat covered in ketchup next to a hamburger on a green plate'. Find frequency of the letter 'g'
[A]: 2


[Q]: Sentence: 'a sheep in a field in front of other sheep'. Find frequency of the letter 'f'
[A]: 3


[Q]: Sentence: 'a man and woman drinking wine and posing for a picture together'. Find frequency of the letter 'n'
[A]:
8