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

Example Input: Sentence: 'a big bowl of brown food halfway in a small oven'. Replace the letter 'v' with 'k' in the sentence.
Example Output: a big bowl of brown food halfway in a small oken

Example Input: Sentence: 'a man holds his hands out in pursuit of a disk'. Replace the letter 'n' with 'o' in the sentence.
Example Output: a mao holds his haods out io pursuit of a disk

Example Input: Sentence: 'a man reading a newspaper while on a train next to bicycles'. Replace the letter 'i' with 'y' in the sentence.
Example Output:
a man readyng a newspaper whyle on a trayn next to bycycles