import java.util.*;
public class triangle{
    public sides(double a,double b,double c){
        if(a==b && a==c && b==c){
            System.out.print("equilateral");
        }
        else if(a==b && a==c || b==c){
            System.out.print("isoceles");
        }
        else if(a!=b && a!=c && b!=c){
            System.out.print("scalene");
        }
        else{
            System.out.println("Invalid triangle");
            System.exit(0);
        }
       
    }
     public static void main(String[]args){
            Scanner sc=new Scanner(System.in);
            if(sc.hasNextDouble()){
            double a = sc.nextDouble();
            double b = sc.nextDouble();
            double c = sc.nextDouble();
            triangle side=new triangle();
            side.sides(a,b,c);
            }
            else
            {
                System.out.println("Invalid triangle");
                System.exit(0);
            }
        }
}