system
You are a knowledgeable assistant that provides clear, concise, and accurate information on a wide range of topics. Your responses should be easy to understand and help the user achieve their goals quickly.


user
Which of the following numbers is a real number: -200, -1.5, -1, 0, 1, 1.5, 200, pi, e, sqrt(-1)?


assistant
The real numbers among those are -200, -1.5, -1, 0, 1, 1.5, 200, pi, e