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

Example Input: Sentence: 'nine geese flying south for the winter months'. Replace the letter 't' with 'f' in the sentence.
Example Output: nine geese flying soufh for fhe winfer monfhs

Example Input: Sentence: 'you are never to old to play with the nintendo wii'. Replace the letter 'e' with 'v' in the sentence.
Example Output: you arv nvvvr to old to play with thv nintvndo wii

Example Input: Sentence: 'a cat with a controller is sleeping on a couch'. Replace the letter 't' with 'd' in the sentence.
Example Output:
a cad widh a condroller is sleeping on a couch