import java.util.Scanner;
public class StackLL
{
Node start=new Node();
Node top=new Node();
Node curr=new Node();
int ch,num;
StackLL()
{
num=0;
start=null;
top=null;
}
void Push(int val)
{
Node t=new Node();
t.info=val;
t.next=null;
if(num++==0)
start=t;
else
top.next=t;
top=t;