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 artists called the tourists near the doctor .
The tourists called the artists .

The president who the doctor recommended introduced the tourist .
The doctor introduced the president .

The president stopped the artists who the judges recognized .

The artists stopped the president .