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

Example Input: Sentence: 'a single person is working in the cluttered kitchen'. Replace the letter 'n' with 'e' in the sentence.
Example Output: a siegle persoe is workieg ie the cluttered kitchee

Example Input: Sentence: 'a hipster riding a skateboard up the side of a wall'. Replace the letter 's' with 'm' in the sentence.
Example Output: a hipmter riding a mkateboard up the mide of a wall

Example Input: Sentence: 'a small kitchen with a table, chairs, fridge and trash can'. Replace the letter 'a' with 'n' in the sentence.
Example Output:
n smnll kitchen with n tnble, chnirs, fridge nnd trnsh cnn