enter code here

 import java.io.*;
 import java.util.*;
 class Node
 {
 int data;
 Node next;
 public Node(int data)
{
this.data = data;
this.next = null;
}
}
public class Solution
{
public Node head;
public void push(int data)//insert at begin
{
Node newNode = new Node(data);
newNode.next = head;
head = newNode;
}
public void pop()//deletion at begin
{
if (head == null) {
    System.out.print("stack underFlow");
    return;
}
 head = head.next;
}
public int maxele(Node head)
{
Node max = head;
Node temp = head;
while(temp!=null)
{
if(max.data>temp.data)
max=temp;
temp = temp.next;
}
return max.data;
}
public void display()
{
Node temp = head;
while(temp!=null)
{
   System.out.print(temp.data+"");
   temp = temp.next;
   }
}
 public static void main(String[] args)
 {
     Scanner sc = new Scanner(System.in);
     Solution obj = new Solution();
    int maximumElement;
    int N,i=0;
    int test;
    N=sc.nextInt();
    while(i<N)
    {
    test = sc.nextInt();
    if(test==1)
    {
    obj.push(sc.nextInt());
    }
    else if(test==2)
    {
    obj.pop();
    }
    else if(test==3)
    {
    maximumElement=obj.maxele(obj.head);
    System.out.println(maximumElement);
    System.out.println();
    }
    i++;
      }
    }
  }