public class Program
    {
        static void Main(string[] args)
        {
            string final = null;
                for (int i = 100; i < 1000; i++)
                {
                    for (int b = 100; b < 1000; b++)
                    {
                        int toCheck = i * b;
                        string stringToCheck;
                        stringToCheck = toCheck.ToString();
                        if (stringToCheck.Equals(Reverse(stringToCheck)))
                        {
                            final = stringToCheck;
                        }
                    }
                }

                Console.WriteLine(final);
                Console.ReadLine();
        }


        public static string Reverse(string s)
        {
            Stack<string> stack = new Stack<string>();

            for (int i = 0; i < s.Length; i++)
                stack.Push(s.Substring(i, 1));

            string ts = string.Empty;
            for (int i = 0; i < s.Length; i++)
                ts += stack.Pop();

            return ts;
        }

    }