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

[EX Q]: Sentence: 'a bird outside standing on a table looking up'. Find frequency of the letter 'b'
[EX A]: 2

[EX Q]: Sentence: 'a plate of food, with broccoli and nuts'. Find frequency of the letter 'b'
[EX A]: 1

[EX Q]: Sentence: 'a living room is full of furniture and other stacks of objects'. Find frequency of the letter 'n'
[EX A]:
3