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

Example Input: Sentence: 'a large table with a green cloth on top'. Replace the letter 'e' with 'i' in the sentence.
Example Output: a largi tabli with a griin cloth on top

Example Input: Sentence: 'a cat sits on the floor next to a purse'. Replace the letter 'a' with 'b' in the sentence.
Example Output: b cbt sits on the floor next to b purse

Example Input: Sentence: 'stop lights hanging on lines during a purple sky night'. Replace the letter 'i' with 'b' in the sentence.
Example Output:
stop lbghts hangbng on lbnes durbng a purple sky nbght