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: 'mannequins are beside a motor scooter inside a display case'. Replace the letter 'l' with 'c' in the sentence.
Example Output: mannequins are beside a motor scooter inside a dispcay case

Example Input: Sentence: 'a black and white photograph of a wall clock'. Replace the letter 'c' with 'x' in the sentence.
Example Output:
a blaxk and white photograph of a wall xloxk