using System;

public class Program

{

    public static void Main()

    {

        var animalType = Console.ReadLine();

        switch(animalType)

        {

            case "dog":

                Console.WriteLine("mammal");

                break;

            case "crocodile":

            case "tortoise":

            case "snake":

                Console.WriteLine("reptile");

                break;

            default:

                Console.WriteLine("unknown");

                break;

        }

    }

}