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 scientist who the tourists helped thanked the actors .
The tourists thanked the scientist .

The artist behind the actors helped the bankers .
The bankers helped the artist .

The author saw the president .

The president saw the author .