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

Example Input: Sentence: 'busy city street with pedestrians and cars with lights all around'. Replace the letter 'r' with 'k' in the sentence.
Example Output: busy city stkeet with pedestkians and caks with lights all akound

Example Input: Sentence: 'a person with a cell phone standing next to a train'. Replace the letter 's' with 't' in the sentence.
Example Output: a perton with a cell phone ttanding next to a train

Example Input: Sentence: 'fries with napkin on the plate on the table'. Replace the letter 'n' with 'l' in the sentence.
Example Output:
fries with lapkil ol the plate ol the table