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

[EX Q]: Sentence: 'a dog sitting in the back of a truck flat bed'. Find frequency of the letter 'h'
[EX A]: 1

[EX Q]: Sentence: 'a person is water skiing and there are birds flying around above them'. Find frequency of the letter 'n'
[EX A]: 5

[EX Q]: Sentence: 'three men are in a kitchen cooking and cutting through a dish'. Find frequency of the letter 'a'
[EX A]:
4