import java.util.*;
class main
{
    public static void main(String[] args)
    {
        Scanner sc=new Scanner(System.in);
        try
        {
            double a=sc.nextDouble();
            double b=sc.nextDouble();
            double c=sc.nextDouble();
            if(a==b && b==c && a==c)
            {
                System.out.print("equilateral");
                return;
            }
            else if(a==b || b==c || a==c)
            {
                System.out.print("isosceles");
                return;
            }
            else if(a!=b!=c)
            {
                System.out.print("scalene");
                return;
            }
        }
        catch(Exception e)
        {
            System.out.print("Invalid triangle");
        }
    }
}