botanics

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Numerics;

namespace Q10235
{
    class Program
    {
        static private BigInteger n; static private bool ntof;
        static void Main(string[] args)
        {
            for (; ; )
            {
            labeln: Console.Write("n>>>");
                ntof = BigInteger.TryParse(Console.ReadLine(), out n);
                if (!ntof) goto labeln;
                Console.WriteLine(isPrime(n) ? isPrime(reverse(n)) && reverse(n) != n ? n + " is emirp." : n + " is prime." : n + " is not prime.");
            }
        }
        static public bool isPrime(BigInteger n)
        {
            int limit = (int)Math.Sqrt((double)n) + 1;
            for (int i = 2; i <= limit; i++)
            {
                if (n % i == 0) return false;
            }
            return true;
        }
        static public BigInteger reverse(BigInteger n)
        {
            string str = "";
            for (int i = 0; i < n.ToString().Length; i++)
            {
                str += n.ToString().Substring(n.ToString().Length - 1 - i, 1);
            }
            return BigInteger.Parse(str);
        }
    }
}