TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a guy surfs a wave with his surfboard'. Find frequency of the letter 's'

SOLUTION: 4

PROBLEM: Sentence: 'four men standing around two pizzas in a conference room'. Find frequency of the letter 't'

SOLUTION: 2

PROBLEM: Sentence: 'a pot of many oranges in a sink'. Find frequency of the letter 'o'

SOLUTION:
3