TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a teenager witting on a futon couch holding gaming controls in both hands'. Find frequency of the letter 'c'

SOLUTION: 3

PROBLEM: Sentence: 'two boys are doing skateboard jumps in the street'. Find frequency of the letter 's'

SOLUTION: 4

PROBLEM: Sentence: 'a man sitting in a stadium seat eating a hot dog'. Find frequency of the letter 's'

SOLUTION:
3