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.

[EX Q]: The author saw the artist .
[EX A]: The artist saw the author .

[EX Q]: The professor by the artists advised the secretaries .
[EX A]: The secretaries advised the professor .

[EX Q]: The athlete who saw the senator called the president .
[EX A]:
The president called the senator .