TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a log in the water with three birds perched on it'. Find frequency of the letter 'r'

SOLUTION: 4

PROBLEM: Sentence: 'a man opening up a package sitting on a couch'. Find frequency of the letter 'n'

SOLUTION: 5

PROBLEM: Sentence: 'an old, run down living room that looks as if it has been burned'. Find frequency of the letter 'l'

SOLUTION:
3