TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'the person rides down the path atop the pink skateboard'. Replace the letter 'e' with 'c' in the sentence.

SOLUTION: thc pcrson ridcs down thc path atop thc pink skatcboard

PROBLEM: Sentence: 'a couple of brown bears walking across a lush green field'. Replace the letter 'w' with 'o' in the sentence.

SOLUTION: a couple of broon bears oalking across a lush green field

PROBLEM: Sentence: 'a very big pretty train in the station'. Replace the letter 'r' with 'y' in the sentence.

SOLUTION:
a veyy big pyetty tyain in the station