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

[Q]: Sentence: 'a row of vintage cars in a grassy field'. Find frequency of the letter 'v'
[A]: 1

[Q]: Sentence: 'a boy that is sitting at a table with pizza'. Find frequency of the letter 's'
[A]: 2

[Q]: Sentence: 'several people on the beach looking at something in the sky'. Find frequency of the letter 'e'
[A]:
8