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

Input: Consider Input: Sentence: 'a man is somewhat hard to be seen in the wave, on his board'. Replace the letter 's' with 'b' in the sentence.

Output: a man ib bomewhat hard to be been in the wave, on hib board

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

Output: subwac train approaching the platform of a subwac station

Input: Consider Input: Sentence: 'a man getting ready to hit a ball at a baseball game'. Replace the letter 'n' with 'v' in the sentence.
Output: a mav gettivg ready to hit a ball at a baseball game