using System;

public class Program

{

    public static void Main()

    {

        int num = int.Parse(Console.ReadLine());

        if (num<100 && num>9)

        {

            Console.WriteLine("double");

            if (num/10==num%10)

                Console.WriteLine("units and tens are equal");

        }

        else

            Console.WriteLine("no");

    }

}