using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace foryuki
{
    class Program
    {
        static int[] n;

        static void Main(string[] args)
        {
            var c = Console.ReadLine().ToCharArray();
            string s;
            int a;
            int max = int.Parse(s = new string(c));
            char w;
            char[] c2 = new char[c.Length];

            for (int i = 0; i < c.Length; i++)
            {
                for (int j = 0; j < c.Length; j++)
                {
                    c.CopyTo(c2, 0);
                    w = c2[i];
                    c2[i] = c2[j];
                    c2[j] = w;

                    a = int.Parse(s = new string(c2));
                    if (a > max)
                    {
                        max = a;
                    }
                }
            }

            Console.WriteLine(max);
        }

        //-------------------------------------------------------------

        static int[] ConvertStringArrayToIntArray(string[] array)
        {
            return Array.ConvertAll(array, str => int.Parse(str));
        }

        static List<int> ConvertStringArrayToIntList(string[] str)
        {
            var list = new List<int>();
            foreach (var c in str)
            {
                list.Add(int.Parse(c));
            }
            return list;
        }
    }
}