using System;

using System.Text;

​

public class Program

{

    public static void Main()

    {

        DoWork("");

    }

​

    internal static void DoWork(string str)

    {

        int i;

        StringBuilder builder = new StringBuilder();

        int Start = str.Length - 1;

        int End = str.Length - 1;

        while (Start > 0)

        {

            if (str[Start] == ' ')

            {

                i = Start + 1;

                while (i <= End)

                {

                    builder.Append(str[i]);

                    i++;

                }

​

                builder.Append(' ');

                End = Start - 1;

            }

​

            Start--;

        }

​

        for (i = 0; i <= End; i++)

        {

            builder.Append(str[i]);

        }

​

        Console.WriteLine(builder.ToString());

    }

}