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

[Q]: Sentence: 'decorated baseball cake in a clear plastic box'. Find frequency of the letter 'k'
[A]: 1


[Q]: Sentence: 'a chair and umbrella on a sandy beach'. Find frequency of the letter 's'
[A]: 1


[Q]: Sentence: 'sign on wall in public restroom stall near sink'. Find frequency of the letter 'l'
[A]:
5