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

namespace MyCompiler {
    class Program {
        public static void Main(string[] args) 
        {
            Console.WriteLine("Hello world!");
            trueorder("hello world");
            trueorder("have a nice day");
        }
        
        public static void trueorder(string str)
        {
            char[]  arr = str.Where(x => char.IsLetter(x)).ToArray();
            Array.Sort(arr);
            Queue<char> qw = new Queue<char>(arr);
            string res = "";
            foreach(var i in str)
            {
                res  += i != ' '?qw.Dequeue().ToString(): " ";
            }
            Console.WriteLine(res);
        }
    }
}