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

Example Input: Sentence: 'two cats sitting on an office chair next to a desk'. Replace the letter 's' with 'j' in the sentence.
Example Output: two catj jitting on an office chair next to a dejk

Example Input: Sentence: 'a bunch of red apples next to a few oranges'. Replace the letter 'n' with 'x' in the sentence.
Example Output: a buxch of red apples xext to a few oraxges

Example Input: Sentence: 'bananas, oranges and apples are in shades of yellow and orange'. Replace the letter 'r' with 'b' in the sentence.
Example Output:
bananas, obanges and apples abe in shades of yellow and obange