//  Decode.java from  Lewis and Loftus, page 508, modified to
//  demonstrate user-defined stack implemeted as a linked list. 

import java.io.*;

// Each node of a Stack object contains a Character data and a 
// reference to the next node. Initially, the stack is defined
// by a reference to the "top" node.

class Stack {

   private StackNode top; 

   public Stack () {
      top = null; 
   }

   public void push (Character nextChar) {

      StackNode node = new StackNode (nextChar);
      node.next = top;
      top = node;
   }

   public Character pop () {
      
      Character data = top.letter;
      top = top.next;
      return data;
   }

   public boolean empty () {
     
      return (top == null);
   }

   public String toString ()  {

      String result = "";
      StackNode current = top;

      while (current != null)  {
         result += current.letter.toString();
         current = current.next;
      }
      return result;
   }

//  An inner class that represents a node in the Stack

   private class StackNode {

      public Character letter;
      public StackNode next;

      public StackNode (Character nextLetter) {
         letter = nextLetter;
         next = null; 
      }
   }
}

public class MyDecode {

   public static void main (String[] args) throws IOException {

      BufferedReader stdin = new BufferedReader 
                (new InputStreamReader (System.in));
  
      Stack word = new Stack();
      String message;
      int index = 0;

      System.out.println ("Enter the coded message:");
      message = stdin.readLine(); 
      System.out.println ("The decoded message is:");

      while (index < message.length()) {
      
         while (index < message.length() && message.charAt(index) != ' ') {
         
           word.push (new Character(message.charAt(index)));
           index++;
         }

         // Print current word in reverse order
         while (!word.empty())
            System.out.print (((Character)word.pop()).charValue());
         System.out.print (" ");
         index++;
      }

      System.out.println();   
   }
}