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

Example Input: Sentence: 'small kit bathroom sink with purple walls and lights on it'. Replace the letter 'o' with 'r' in the sentence.
Example Output: small kit bathrrrm sink with purple walls and lights rn it

Example Input: Sentence: 'two zebras are snuggling at the zoo in their display area'. Replace the letter 'e' with 'z' in the sentence.
Example Output: two zzbras arz snuggling at thz zoo in thzir display arza

Example Input: Sentence: 'an executive at a meeting prepares to cut the cake'. Replace the letter 'u' with 'o' in the sentence.
Example Output:
an execotive at a meeting prepares to cot the cake