In this task, you need to replace a letter in the sentence with another given letter.

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

Ex Output:
cowwuter trains on tracks next to paved platforw

Ex Input:
Sentence: 'a toilet and a microwave sitting out for the trash'. Replace the letter 'i' with 's' in the sentence.

Ex Output:
a toslet and a mscrowave ssttsng out for the trash

Ex Input:
Sentence: 'a couple of coaches in a cluttered living room'. Replace the letter 'a' with 'f' in the sentence.

Ex Output:
f couple of cofches in f cluttered living room