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

Example Input: Sentence: 'a red hydrant is sitting on the sidewalk in the city'. Replace the letter 'n' with 'r' in the sentence.
Example Output: a red hydrart is sittirg or the sidewalk ir the city

Example Input: Sentence: 'a seafood dish served over a bowl of white rice'. Replace the letter 'e' with 'u' in the sentence.
Example Output: a suafood dish survud ovur a bowl of whitu ricu

Example Input: Sentence: 'potted plants near a park and trees'. Replace the letter 'e' with 'x' in the sentence.
Example Output:
pottxd plants nxar a park and trxxs