instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a black animal in dirt area below trees and rocks'. Find frequency of the letter 'n'
answer:
3


question:
Sentence: 'a couple of buildings that has a bus out front'. Find frequency of the letter 'a'
answer:
4


question:
Sentence: 'a green and yellow truck is driving on the road'. Find frequency of the letter 'o'
answer:

3