/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	
	public static class Node {
        int value;
        Node next;
    }

    static class LinkedList {
        Node first;
    }
    
    
 public static void main(String[] args) {
        Node n1 = new Node();
        n1.value = 3;
        Node n2 = new Node();
        n2.value = 2;
        n2.next = n1;
        Node n3 = new Node();
        n3.value = 1;
        n3.next = n2;

        LinkedList list = new LinkedList();
        list.first = n3;

        Node tNode = list.first;
        while (tNode != null) {
            System.out.println(tNode.value + " ");
            tNode = tNode.next;
        }

        tNode = list.first;
        Node oldNext = null;
        while (tNode != null) {
            Node next = tNode.next;
            tNode.next = oldNext;
            oldNext = tNode;
            if(next == null) {
                list.first = tNode;
            }
            tNode = next;
        }

        tNode = list.first;
        while (tNode != null) {
            System.out.println(tNode.value + " ");
            tNode = tNode.next;
        }
}
}