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

[Q]: Sentence: 'a picture of two computers on a table'. Find frequency of the letter 'r'
[A]: 2


[Q]: Sentence: 'a cat sprawls out and sleeps on its back on a lounge chair with an acorn theme'. Find frequency of the letter 'r'
[A]: 3


[Q]: Sentence: 'a number of animals in a field near bushes'. Find frequency of the letter 'e'
[A]:
4