using System;

public class StringConcat

{

    public static void Main()

    {

        Console.WriteLine("Enter a string : ");

        String str1 = Console.ReadLine();

        //char[] charArray = str1.ToCharArray();

        char[] str2 = str1.ToCharArray();

        Array.Sort(str2);

        foreach(char c in str2) {   

            Console.Write(c);

        }

    }

}