using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Text;
using System.Text.RegularExpressions;
using System.Linq;

class Magatro
{
    static void Main()
    {

        string N = Console.ReadLine();
        long max = long.Parse(N);
        for (int i = 1; i < N.Length; i++)
        {
            for (int j = 0; j < i; j++)
            {
                char[] c = N.ToArray();
                swap(ref c[i], ref c[j]);
                long q = long.Parse(new string(c));
                max = Math.Max(max, q);
            }
        }
        Console.WriteLine(max);
    }
    static void swap(ref char a, ref char b)
    {
        char t = a;
        a = b;
        b = t;
    }
}