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 tourist called the doctor .
The doctor called the tourist .

The artist by the tourist encouraged the author .
The author encouraged the artist .

The judges recommended the banker who stopped the president .

The president recommended the judges .