import java.util.Scanner;
public class Node
{
int info;
Node next,prev;
Node left,right;
}
public class QueueLL
{
Node start=new Node();
Node end=new Node();
Node curr=new Node();
int ch,num;
Object obj=new Object();
QueueLL()
{
start=null;
end=null;
num=0;
}
void Add(int val)
{