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

[EX Q]: Sentence: 'the receipts from a meal at a restaurant are for  a sandwich, chili, and apple'. Find frequency of the letter 'u'
[EX A]: 1

[EX Q]: Sentence: 'a giraffe sticking it's tongue out near a window'. Find frequency of the letter 'a'
[EX A]: 4

[EX Q]: Sentence: 'a young man performing a skateboard trick on a ramp'. Find frequency of the letter 'm'
[EX A]:
3