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

Example Input: Sentence: 'three laptops are turned on lined up on a table'. Replace the letter 't' with 'g' in the sentence.
Example Output: ghree lapgops are gurned on lined up on a gable

Example Input: Sentence: 'giraffe standing on a pile of rocks reaching up to a branch with its mouth'. Replace the letter 'g' with 'n' in the sentence.
Example Output: niraffe standinn on a pile of rocks reachinn up to a branch with its mouth

Example Input: Sentence: 'two green and white street signs reading "crooks rd" and "corporate dr."'. Replace the letter 's' with 'i' in the sentence.
Example Output:
two green and white itreet iigni reading "crooki rd" and "corporate dr."