import java.io.*;
import java.util.Scanner;
class node
{
    public int val;
    public node link;
    public void print()
    {
        System.out.print(val);
    }
};
class linkedList
{
    private node first;
    public linkedList()
    {
        first=null;
    }
    public boolean isEmpty()
    {
        return (first==null);
    }
    public void insert(int num)
    {
        node n=new node();
        n.val=num;
        if(isEmpty())
        {
            n.link=null;
        }
        else
        {
         n.link=first;
        }
        first=n;
    }
    public void pop(int num)
    {
        node n1=first.link,n2=first;

        while(n1.link!=null)
        {
            if(n1.val==num)
            {
                n2.link=n1.link;
                System.out.print(n1.val+"has been removed from list");
                break;
            }
            n2=n2.link;
            n1=n1.link;
        }
    }
    public void disp()
    {
        node n=first;
        while(n.link!=null)
        {
            System.out.print(n.val+" ");
        }
    }
};
class program
{
    public static void main(String args[])
    {
        linkedList l=new linkedList();
        int choice,a,ch=1;
        Scanner scan=new Scanner(System.in);
        while(ch==1)
        {

            System.out.print("1.inserting \n2.deleteing a purticular value \n3.displaying\n4.exit");
            choice=scan.nextInt();
            switch(choice)
            {
                case 1:System.out.println("enter the number to be inserted");
                       a=scan.nextInt();
                       l.insert(a);
                    break;
                case 2: System.out.println("enter the number to be deleted");
                       a=scan.nextInt();
                       l.delete(a);
                    break;
                case 3:l.display();
                    break;

                case 4:ch=0;
                    break;
            }
        }
    }
}