TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a brown door  that says gentlemen and a toilet'. Replace the letter 'o' with 'f' in the sentence.

SOLUTION: a brfwn dffr  that says gentlemen and a tfilet

PROBLEM: Sentence: 'a young man playing tennis and preparing to hit the ball'. Replace the letter 'e' with 'c' in the sentence.

SOLUTION: a young man playing tcnnis and prcparing to hit thc ball

PROBLEM: Sentence: 'a person holding a cell phone while seated'. Replace the letter 'l' with 'p' in the sentence.

SOLUTION:
a person hopding a cepp phone whipe seated