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 car accident has slowed traffic as a clean up crew works'. Find frequency of the letter 'f'
[EX A]: 2

[EX Q]: Sentence: 'a piece of red luggage sitting against a dilapidated wall'. Find frequency of the letter 'g'
[EX A]:
5