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

class Program
{
    static void Main()
    {
        char[] N = Console.ReadLine().ToCharArray();

        int idx = Array.LastIndexOf(N, N.Max());

        char w = N[0];
        N[0] = N[idx];
        N[idx] = w;

        Console.WriteLine(new string(N));
    }
}