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

[EX Q]: Sentence: 'a table topped with a cupcake on a picture of a cupcake'. Find frequency of the letter 'o'
[EX A]: 3

[EX Q]: Sentence: 'a young boy holding a piece of paper on top of a table'. Find frequency of the letter 'y'
[EX A]: 2

[EX Q]: Sentence: 'a cat that is perched directly over the keyboard of a laptop'. Find frequency of the letter 'd'
[EX A]:
3