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

Example Input: Sentence: 'this is a cute dog sticking his head out of the window of a red car'. Replace the letter 'e' with 'z' in the sentence.
Example Output: this is a cutz dog sticking his hzad out of thz window of a rzd car

Example Input: Sentence: 'a dog drinking out of a bowl of water'. Replace the letter 'w' with 'k' in the sentence.
Example Output: a dog drinking out of a bokl of kater

Example Input: Sentence: 'a large elephant walking down a road past wild brush'. Replace the letter 'l' with 'r' in the sentence.
Example Output:
a rarge erephant warking down a road past wird brush