import java.lang.*;

class Demo
{
    public int i;
    public final int j=20;
    public final int k;

    public Demo()  //:j(10)  in c++
    {
        this.i=10;
        this.k=30;
    }

    public Demo(int a,int b)
    {
        this.i=a;
        this.k=b;
    }

    public void fun()
    {
        i++;
        //j++;  error
        //k++;  error
        System.out.println(i);
    }
}

class Final1
{
    public static void main(String arg[])
    {
        Demo obj1=new Demo();
        Demo obj2=new Demo(11,21);
        obj1.fun();
        obj2.fun(); 
        System.out.println(obj1.i);
        System.out.println(obj1.j);
        System.out.println(obj1.k);
        System.out.println(obj2.i);
        System.out.println(obj2.j);
        System.out.println(obj2.k);
    }
}