TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a close up of a train on a track in the dark'. Find frequency of the letter 'a'

SOLUTION: 6

PROBLEM: Sentence: 'surfboard being displayed in stor window with clothes behind it'. Find frequency of the letter 't'

SOLUTION: 4

PROBLEM: Sentence: 'two men in suits pose next to each other'. Find frequency of the letter 'n'

SOLUTION:
3