import java.util.Scanner;

// 三角形的定义
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            int a = sc.nextInt();
            int b = sc.nextInt();
            int c = sc.nextInt();
            // 是否可以构成三角形,任意两条边之和大于第三条边
            if (a + b > c && a + c > b && b + c > a) {
                if (a == b && b == c) {
                    System.out.println("Equilateral triangle!");
                } else if (a == b || a == c || b == c) {
                    System.out.println("Isosceles triangle!");
                } else {
                    System.out.println("Ordinary triangle!");
                }
            } else {
                System.out.println("Not a triangle!");
            }
        }


    }
}