class Program
    {
        static void Main(string[] args)
        {
            string str = Console.ReadLine();
            int[] numList = Array.ConvertAll(str.ToCharArray(), num => int.Parse(num.ToString()));
            Array.Sort(numList);
            Array.Reverse(numList);
            for (int i = numList.Length-1; i > 0; i--)
            {
                if (numList[i] != numList[i - 1])
                {
                    int change = numList[i];
                    numList[i] = numList[i - 1];
                    numList[i - 1] = change;
                    break;
                }
            }

            if (numList[0] == 0 || String.Join("", numList) == str || String.Join("", numList).Length != str.Length)
            {
                Console.WriteLine(-1);
            }
            else
            {
                Console.WriteLine(String.Join("", numList));
            }

        }
    }