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 secretaries stopped the presidents .
The presidents stopped the secretaries .

The presidents next to the scientists saw the students .
The scientists saw the presidents .

The athletes that contacted the secretaries called the judge .

The judge called the athletes .