TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'there is a sandwich with a lot of meat cut in half'. Find frequency of the letter 'a'

SOLUTION: 5

PROBLEM: Sentence: 'men standing in the grass with a frisbee'. Find frequency of the letter 'a'

SOLUTION: 3

PROBLEM: Sentence: 'there is a man who is getting his sideburns cut'. Find frequency of the letter 'n'

SOLUTION:
3