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

[EX Q]: Sentence: 'a closeup view of a bathroom sink, that is very modern'. Find frequency of the letter 'e'
[EX A]: 4

[EX Q]: Sentence: 'a man hits a tennis ball with a racket on the court'. Find frequency of the letter 'c'
[EX A]: 2

[EX Q]: Sentence: 'small group of sheep grazing on grass in snow covered field'. Find frequency of the letter 'a'
[EX A]:
3