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.
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Question: The president behind the doctors called the secretary .

Answer: The secretary called the president .


Question: The artist recommended the senators by the student .

Answer: The student recommended the artist .


Question: The scientist that encouraged the athlete introduced the professor .

Answer:
The professor introduced the scientist .