TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a stop sign next to houses with christmas lights'. Find frequency of the letter 's'

SOLUTION: 7

PROBLEM: Sentence: 'a group of people walking down a rain soaked street with umbrellas'. Find frequency of the letter 'w'

SOLUTION: 3

PROBLEM: Sentence: 'a man with his friend throwing a frisbee'. Find frequency of the letter 'o'

SOLUTION:
1