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

[EX Q]: Sentence: 'a toilet of some sort near a sink of some sort'. Find frequency of the letter 'o'
[EX A]: 7

[EX Q]: Sentence: 'a baseball themed birthday cake is on a serving tray'. Find frequency of the letter 'g'
[EX A]: 1

[EX Q]: Sentence: 'green cake in the shape of a truck holding sticks'. Find frequency of the letter 's'
[EX A]:
3