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 author in front of the tourists avoided the actors .
The actors avoided the tourists .

The doctors stopped the athlete in front of the author .
The athlete stopped the author .

The professor behind the presidents stopped the artist .

The artist stopped the presidents .