import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        while(scan.hasNextInt()) {
            int a = scan.nextInt();
            int b = scan.nextInt();
            int c = scan.nextInt();
            T t = new T();
            t.info(a, b, c);
            
        }
    }
}
class T {
    public void info(int a, int b, int c) {
        int max = (a > b ? a : b) > c ? (a > b ? a : b) : c;
        if(a + b + c > 2 * max) {
            if(a == b && b == c) {
                System.out.println("Equilateral triangle!");
            } else if((a == b && a != c) || (a == c && a != b) || (b == c && b != a)) {
                System.out.println("Isosceles triangle!");
            } else {
                System.out.println("Ordinary triangle!");
            }
        } else {
            System.out.println("Not a triangle!");
        }
    }
}