TASK DEFINITION: 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.
PROBLEM: The artist called the president by the bankers .

SOLUTION: The president called the artist .

PROBLEM: The professors helped the doctor that the manager mentioned .

SOLUTION: The doctor helped the manager .

PROBLEM: The doctors introduced the bankers .

SOLUTION:
The bankers introduced the doctors .