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

Example Input: Sentence: 'a black and white photo of a bird clouds sand and water'. Replace the letter 'b' with 'p' in the sentence.
Example Output: a plack and white photo of a pird clouds sand and water

Example Input: Sentence: 'a fire hydrant with a message painted on it'. Replace the letter 'n' with 'j' in the sentence.
Example Output: a fire hydrajt with a message paijted oj it

Example Input: Sentence: 'a cart with a load of suitcases pile on it'. Replace the letter 'r' with 'w' in the sentence.
Example Output:
a cawt with a load of suitcases pile on it