using System;

​

public class Program

{

    public static void Main()

    {

        Program obj = new Program();

        //string str = "493853289475554";

        //string str = "12345678";

        //string str = "493853288475554";

        string str = "56981557155672";

        string final = "";

        if (str.Length > 8)

        {

            for (int i = 0; i <= str.Length - 1;)

            {

                if (Convert.ToInt64((str[i].ToString() + str[i + 1].ToString())) < 80)

                {

                    //Console.Write(str[i].ToString() + str[i+1].ToString() + " ");                 

                    string val1 = (str[i].ToString() + str[i + 1].ToString() + " ");

                    final = final + val1;

                    i = i + 2;

                }

                else

                {

                    //Console.Write(str[i].ToString() + " ");

                    string val2 = (str[i].ToString() + " ");

                    final = final + val2 ;

                    i = i + 1;

                }

            }

            //Console.WriteLine(final);

            bool flag1 = obj.uniqueCharactersFinal(final);

            if (flag1 == true)

            {

                Console.WriteLine(final);

            }

            else

            {

                Console.WriteLine("N/A");

            }

        }

        else

        {

            bool flag = obj.uniqueCharacters(str);

            if (flag == true)

            {

                Console.Write(str);

            }

            else

            {

                Console.Write("N/A");

            }

        }

    }

​

    bool uniqueCharacters(String str)

    {

        for (int i = 0; i < str.Length; i++)

            for (int j = i + 1; j < str.Length; j++)

                if (str[i] == str[j])

                    return false;

        return true;

    }

    bool uniqueCharactersFinal(String str)

    {

        string[] str1 = new []{ str };

        for (int i = 0; i < str1.Length; i++)

            for (int j = i + 1; j < str1.Length; j++)

                if (str1[i] == str1[j])

                    return false;

        return true;

    }

}