import java.io.*;
import java.util.*;

class MultipleChoice
{
    public static void main(String[] args)
    {
        String color = "blue";
        if(color.equals("blue"))
        {
            System.out.println("blue");
        }
        else
        {
            if(color.equals("red"))
            {
                System.out.println("red");
            }
            else
            {
                if(color.equals("purple"))
                {
                    System.out.println("purple");
                }
                else
                {
                    System.out.println("who knows?");
                }
            }
        }
    }

}