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

Example Input: Sentence: 'a person is riding a motorcycle as part of some kind of performance'. Replace the letter 'm' with 'a' in the sentence.
Example Output: a person is riding a aotorcycle as part of soae kind of perforaance

Example Input: Sentence: 'two children struggle over a bat in their playroom'. Replace the letter 't' with 'v' in the sentence.
Example Output: vwo children svruggle over a bav in vheir playroom

Example Input: Sentence: 'a two level bus on a city street with a billboard on the side of two men in polo shirts'. Replace the letter 'm' with 'u' in the sentence.
Example Output:
a two level bus on a city street with a billboard on the side of two uen in polo shirts