class Program
    {
        static void Main(string[] args)
        {
            string str = Console.ReadLine();
            List<char> chars = ChangeCharArray(str);
            int[] countList = new int[10];
            countList = NumberCount(countList, chars);
            Array.Reverse(countList);
            for(int i = 0; i < 10; i++)
            {
                PushNumber(i,countList);
            }
            Console.WriteLine();
        }

        private static void PushNumber(int nowNumber, int[] countList)
        {
            for (int i = 0; i < countList[nowNumber]; i++)
            {
                Console.Write(9 - nowNumber);
            }
        }

        private static int[] NumberCount(int[] countList, List<char> chars)
        {
            foreach (char c in chars)
            {
                countList[int.Parse(c.ToString())]++;
            }
            return countList;
        }

        private static List<char> ChangeCharArray(string str)
        {
            List<char> chars = new List<char>();
            for (int i = 0; i < str.Length; i++)
            {
                chars.Add(str[i]);
            }
            return chars;
        }
    }