TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a couple of kids with rackets on a court'. Replace the letter 'u' with 'd' in the sentence.

SOLUTION: a codple of kids with rackets on a codrt

PROBLEM: Sentence: 'commuter trains on tracks next to paved platform'. Replace the letter 'm' with 'w' in the sentence.

SOLUTION: cowwuter trains on tracks next to paved platforw

PROBLEM: Sentence: 'a train sits parked on the tracks in front of a billboard'. Replace the letter 'i' with 'l' in the sentence.

SOLUTION:
a traln slts parked on the tracks ln front of a blllboard