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

Example Input: Sentence: 'a woman on a cell phone on city street'. Replace the letter 'e' with 'a' in the sentence.
Example Output: a woman on a call phona on city straat

Example Input: Sentence: 'a cat is watching a computer with a video of a cat'. Replace the letter 't' with 'a' in the sentence.
Example Output: a caa is waaching a compuaer wiah a video of a caa

Example Input: Sentence: 'a living room couch with a display of large mirror and flowers'. Replace the letter 't' with 'e' in the sentence.
Example Output:
a living room couch wieh a display of large mirror and flowers