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

public class car{
    void run(){
        System.out.println("car is running");
    }
}

// The main method must be in a class named "Main".
public class Main extends car {
    void run(){
        System.outout.println("audi is running");
    }
    public static void main(String[] args) {
        System.out.println("Hello world!");
        Main b = new Main();
        b.run();
    }
}