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: 'a girl laying on a bed posing for a picture'. Find frequency of the letter 'i'
[EX A]: 4

[EX Q]: Sentence: 'a fire hydrant and a sign are in the grass'. Find frequency of the letter 'g'
[EX A]:
2