import java.util.Scanner;
public class Main {
    
    public static void main(String[] args) {
        
        Scanner sc = new Scanner(System.in);
        while(sc.hasNextInt()) {
            int a = sc.nextInt();
            int b = sc.nextInt();
            int c = sc.nextInt();
            if(a + b > c && a + c > b && b + c > a) {
                if(a==b && b==c && a==c) {
                    System.out.println("Equilateral triangle!");
                } else if(a==b || b==c || a==c) {
                    System.out.println("Isosceles triangle!");
                } else {
                    System.out.println("Ordinary triangle!");
                }
            } else {
                System.out.println("Not a triangle!");
            }
        }
    }
}