namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Enter string: ");
            string s = Console.ReadLine();
            if (IsSymm(s)) Console.WriteLine("Symmetric"); else Console.WriteLine("Non-symmetric");    
            Console.ReadLine();
        }

        static bool IsSymm(string s)
        {
            return (s.Length > 1) ? ((s[0]==s[s.Length - 1]) ? (IsSymm(s.Substring(1, s.Length - 2)) && true) : false) : true;
        }
    }
}