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

[Q]: Sentence: 'a black animal in dirt area below trees and rocks'. Find frequency of the letter 'n'
[A]: 3

[Q]: Sentence: 'a bird is standing on the ledge of the building'. Find frequency of the letter 't'
[A]: 3

[Q]: Sentence: 'a child flies his kite on the beach'. Find frequency of the letter 'h'
[A]:
4