using System;

using System.Globalization;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(Decrypt1("0B031D00180003030A07"));

    }

        public static string Decrypt1(string s)

        {

            string functionReturnValue = null;

            if (string.IsNullOrEmpty(s))

            {

                functionReturnValue = "";

            }

            else

            {

                string r = null;

                int ch;

​

                for (int i = 0; i < s.Length / 2; i++)

                {

                    ch = int.Parse(s.Substring((i) * 2, 2), NumberStyles.AllowHexSpecifier);

                    ch = ch ^ 111;

                    r = r + (char)(ch);

                }

                var charArray = r.ToCharArray();

                Array.Reverse(charArray);

                functionReturnValue = new string(charArray);

            }

            return functionReturnValue;

        }

}