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 scientists supported the senator who the managers encouraged .
The senator supported the scientists .

The doctors by the actor called the president .

The president called the doctors .