TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a man makes some cock tales at a desk'. Find frequency of the letter 'k'

SOLUTION: 3

PROBLEM: Sentence: 'a crowd of people skiing and enjoying the snow'. Find frequency of the letter 'o'

SOLUTION: 5

PROBLEM: Sentence: 'an elephant with tusks walks on concrete and rocky walls and boulders are near him'. Find frequency of the letter 'w'

SOLUTION:
3