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

[EX Q]: Sentence: 'some giraffes moving across a big grass field'. Find frequency of the letter 'e'
[EX A]: 3

[EX Q]: Sentence: 'there is no image here to provide a caption for'. Find frequency of the letter 'o'
[EX A]: 5

[EX Q]: Sentence: 'fathers and children playing sports in a back yard'. Find frequency of the letter 'c'
[EX A]:
2