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

Example Input: Sentence: 'an umbrella sitting on top of a hill next to a body of water'. Replace the letter 't' with 'b' in the sentence.
Example Output: an umbrella sibbing on bop of a hill nexb bo a body of waber

Example Input: Sentence: 'a red park ride bus at a curb with a green/white bus behind'. Replace the letter 'h' with 'x' in the sentence.
Example Output: a red park ride bus at a curb witx a green/wxite bus bexind

Example Input: Sentence: 'group of uniformed individuals reaching down and cutting through a cake'. Replace the letter 'p' with 'w' in the sentence.
Example Output:
grouw of uniformed individuals reaching down and cutting through a cake