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

[Q]: Sentence: 'a picture of a machine built next to a street'. Find frequency of the letter 'x'
[A]: 1

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

[Q]: Sentence: 'a group of three stuffed animals sitting on a counter'. Find frequency of the letter 's'
[A]:
3