import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
        int c = sc.nextInt();
        if (a==b&&b==c&&a==c) {
            System.out.println("Equilateral triangle!");
        } else if (a+b>c && b==a || b==c || a==c) {
            System.out.println("Isosceles triangle!");
        } else if(a+b>c&&a+c>b&&b+c>a){
            System.out.println("Ordinary triangle!");
        } else if(a+b>=c&&a+c>=b&&b+c>=a){
            System.out.println("Not a triangle!");
        }
    }
            }