using System;

public class Program

{

    public static void Main()

    {

        string animal = Console.ReadLine();

        switch (animal)

        {

            case"dog":

                Console.WriteLine("mammal");

                break;

           case"crocodile":

           case"tortoise":

           case"snake":

                 Console.WriteLine("reptile");

                 break;

        default:

                 Console.WriteLine("unknown");

                break;

        }

    }  

}