New name after duplicating existing entry

Imagine I have list of names. User could duplicate one of the names but the system requires that each name is unique. To save users time, the name field of the duplicate name is already prefilled. What is the best way to display a unique item?

So for example, imagine a list like this:

  • Lorem ipsum dolor
  • Sit amet
  • Consectetuer adipiscing

After duplication of the last name, should it be named 'Consectetuer adipiscing copy', 'Consectetuer adipiscing 1', or something else?