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 student mentioned the doctor .

Answer: The doctor mentioned the student .


Question: The actors called the presidents .

Answer: The presidents called the actors .


Question: The doctor who helped the tourists advised the professor .

Answer:
The professor advised the tourists .