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

Example Input: Sentence: 'the living room is designed with brown and beige colors'. Replace the letter 'i' with 'b' in the sentence.
Example Output: the lbvbng room bs desbgned wbth brown and bebge colors

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 couple of giraffes being feed by people at the zoo'. Replace the letter 't' with 'v' in the sentence.
Example Output:
a couple of giraffes being feed by people av vhe zoo