import java.util.*;
import java.lang.*;
import java.io.*;



  /* inheritance is used to borrow properties
       
        for ex:- phone ----> smart phone         jese phone se smart phone 
        bnya humne phone me hi kuchh modification krke usko hi smartphone me convert kr diya
        
        super class ------> sub class     */


class Base {
int a,b;

  void  setA(int a){
        this.a=a;
    }
    int getA(){
        System.out.println("i am in base class now");
        return a;
    }
    
}/* this is our base class if we need same code in other class
so in simple we copy the code butwhen wehave to change the code
    we have to change in all claass so there we use inheritance*/

// making new class 
// we use extends base it mean base class ka sara code isme aajayega 
// agr hum base class me kucchh change krenge toh isme v ho jayga

class Derived extends Base {
    int y;
      void  setY(int y){
        this.y=y;
    }
    int getY(){
        System.out.println("i am in derived class now");
        return y;
}}
// yeh toh ho gya hum is base class or kucch extra v add kr skte h
// for ex new getter setter add kr do yaa kucch v



class Main {
    public static void main(String[] args) {
        System.out.println("Hello world!");

        // object for base class
        Base obj1 = new Base();
    
        obj1.setA(123);
        System.out.println(obj1.getA());

// object for derived class 
        Derived obj2 = new Derived();
        obj2.setA(15);
 System.out.println(obj2.getA());
        // humne y add kiya ab usko access krte h 
        obj2.setY(66);
         System.out.println(obj2.getY());
        



        
    }
}