import java.util.Scanner;
import java.util.Arrays;
public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        while(scan.hasNextLine()) {
            String inStrs = scan.nextLine();
            String[] strs = inStrs.split(" ");
            double[] strDoub = new double[3];
            for(int i = 0; i < 3; i++) {
                strDoub[i] = Double.parseDouble(strs[i]);
            }
            Arrays.sort(strDoub);
            if(strDoub[0] + strDoub[1] <= strDoub[2]) {//不能构成三角形
                System.out.println("Not a triangle!");
            } else if(strDoub[0] == strDoub[1] && strDoub[1] == strDoub[2]) {//等边三角形
                System.out.println("Equilateral triangle!");
            } else if(strDoub[0] == strDoub[1] || strDoub[1] == strDoub[2]) {//等腰三角形
                System.out.println("Isosceles triangle!");
            } else {//普通三角形
                System.out.println("Ordinary triangle!");
            }
        }
    }
}