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 with a large grey and black beard and glasses and a tie'. Find frequency of the letter 'e'

SOLUTION: 5

PROBLEM: Sentence: 'two people in a snowy place near a wooden fence'. Find frequency of the letter 'n'

SOLUTION: 5

PROBLEM: Sentence: 'many animals in a large field with trees near by'. Find frequency of the letter 'a'

SOLUTION:
6