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

Example Input: Sentence: 'two girls holding blue umbrellas wearing shirts and plastic'. Replace the letter 'd' with 'y' in the sentence.
Example Output: two girls holying blue umbrellas wearing shirts any plastic

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

Example Input: Sentence: 'the fixings of a banana treat with a completely made one in the background'. Replace the letter 'h' with 'v' in the sentence.
Example Output:
tve fixings of a banana treat witv a completely made one in tve background