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

[EX Q]: Sentence: 'two giraffes standing next to some trees'. Find frequency of the letter 'f'
[EX A]: 2

[EX Q]: Sentence: 'a cooked pizza on a silver platter with another in the background'. Find frequency of the letter 'e'
[EX A]: 5

[EX Q]: Sentence: 'a single giraffe walking through some trees'. Find frequency of the letter 'o'
[EX A]:
2