package test;

public class Main {

 static class Node {
 Node next;
 int value;

 public Node(int value) {
 this.value = value;
 }
 }

 public static Node resolution(Node header) {
 if (header == null) {
 return null;
 }
 Node p = header;
 Node q = null;
 Node newHeader = null;
 Node newNext = null;
 boolean isPreSame = false;
 while (p != null) {
 if (p.next == null) {
 if (!isPreSame) {
 newNext.next = new Node(p.value);
 }
 } else {
 q = p.next;
 if (p.value != q.value) {
 if (!isPreSame) {
 if (newHeader == null) {
 newNext = p;
 newHeader = newNext;
 } else {
 newNext.next = new Node(p.value);
 newNext = newNext.next;
 }
 }
 isPreSame = false;
 } else {
 isPreSame = true;
 }
 }
 p = p.next;
 }
 return newHeader;
 }

 public static void main(String[] args) {
 // Scanner input=new Scanner(System.in);
 // String str=input.next();
 System.out.println("hello world");
 Node node1 = new Node(1);
 Node node2 = new Node(2);
 Node node3 = new Node(3);
 Node node4 = new Node(3);
 Node node5 = new Node(4);
 Node node6 = new Node(4);
 Node node7 = new Node(5);
 node1.next = node2;
 node2.next = node3;
 node3.next = node4;
 node4.next = node5;
 node5.next = node6;
 node6.next = node7;
 Node newHeader = resolution(node1);
 while (newHeader != null) {
 System.out.println(newHeader.value);
 newHeader = newHeader.next;
 }
 }
}