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

[EX Q]: Sentence: 'a teenager witting on a futon couch holding gaming controls in both hands'. Find frequency of the letter 'c'
[EX A]: 3

[EX Q]: Sentence: 'a red stop sign with street signs above it'. Find frequency of the letter 't'
[EX A]: 5

[EX Q]: Sentence: 'a black and white photo of a woman on her mobile phone'. Find frequency of the letter 'o'
[EX A]:
7