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

[EX Q]: Sentence: 'there are two men sitting on a couch playing video games'. Find frequency of the letter 'v'
[EX A]: 1

[EX Q]: Sentence: 'the sun goes down over a bike tied to a bench at the beach'. Find frequency of the letter 't'
[EX A]: 5

[EX Q]: Sentence: 'black eagle sitting on the back of a blue bicycle'. Find frequency of the letter 'n'
[EX A]:
2