In this task, you are given a premise sentence. Your task is to write a new sentence by substituting the subject and object (i.e., the input's subject should be output's object and vice versa.). The generated sentence must be fluent and shouldn't change the voice (i.e., passive or active) of the input.

The student saw the doctor .
The doctor saw the student .

The professors that called the president avoided the student .
The student avoided the president .

The judge advised the lawyer next to the athlete .

The athlete advised the judge .