using System;
using System.Linq;
using System.Collections.Generic;

namespace Algorithm
{
    class Program
    {
        static void Main(string[] args)
        {
            var X = Console.ReadLine();
            var ans = X.OrderByDescending(z => z).ToArray();
            var bef = new string(ans);

            for (var i = ans.Length - 2; i >= 0; i--)
            {
                Swap(ref ans[i], ref ans[i + 1]);
                if (ans[0] != '0' && new string(ans) != bef)
                {
                    Console.WriteLine(new string(ans));
                    return;
                }
            }

            Console.WriteLine(-1);
        }

        public static void Swap<T>(ref T one, ref T two)
        {
            var temp = one;
            one = two;
            two = temp;
        }
    }
}