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

[EX Q]: Sentence: 'a woman swinging a tennis racquet towards a tennis ball'. Find frequency of the letter 'e'
[EX A]: 3

[EX Q]: Sentence: 'the miniature, elaborate exhibit depicts an ancient boating scene'. Find frequency of the letter 'n'
[EX A]: 6

[EX Q]: Sentence: 'a person skiing down a mountain of snow'. Find frequency of the letter 'n'
[EX A]:
6