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

Ex Input:
Sentence: 'subway train approaching the platform of a subway station'. Replace the letter 'y' with 'c' in the sentence.

Ex Output:
subwac train approaching the platform of a subwac station


Ex Input:
Sentence: 'a giraffe standing alone with a low fence behind it'. Replace the letter 't' with 'o' in the sentence.

Ex Output:
a giraffe soanding alone wioh a low fence behind io


Ex Input:
Sentence: 'a stop sign on a street next to trees and a building'. Replace the letter 'a' with 'h' in the sentence.

Ex Output:

h stop sign on h street next to trees hnd h building