abstract class Shape
{
    // Placeholder, we expect Circle/Square to override
    public abstract double getArea( );   // Abstract method ==== PLACEHOLDER
}

class Circle extends Shape
{
    public Circle( double rad )
    {
        radius = rad;
    }
    
    public String toString( )
    {
        return "Circle with radius " + radius;
    }
    
    public double getArea( )
    {
        return 3.14 * radius * radius;
    }
    
    private double radius;
}

class Square extends Shape
{
    public Square( double s )
    {
        side = s;
    }
    
    public String toString( )
    {
        return "Square with side " + side;
    }
    
    public double getArea( )
    {
        return side * side;
    }
    
    private double side;
}

class Rectangle extends Shape
{
    public Rectangle( double len, double wid )
    {
        length = len;
        width = wid;
    }
    
    public String toString( )
    {
        return "Rectangle with dimensions " + length + "x" + width;
    }
    
    public double getArea( )
    {
        return length * width;
    }
    
    private double length;
    private double width;
}
public class Day3
{
    public static void printAll( Object [ ] arr )
    {
        for( Object obj : arr )
            System.out.println( obj );
    }
    
    public static double totalArea( Shape [ ] arr )
    {
        double sum = 0.0;
        
        for( Shape s : arr )
            if( s != null )
                sum += s.getArea( );
                    
        return sum;
    }
 
      
    public static void main( String [ ] args )
    {
        Circle [ ] arr1 = new Circle[ 4 ];
        Square [ ] arr2 = new Square[ 3 ];
        Rectangle [ ] arr3 = new Rectangle[ 2 ];
        
        Shape [ ] arr4 = new Shape[ 6 ];
        
        arr4[ 0 ] = new Circle( 3.0 );
        arr4[ 1 ] = new Circle( 1.0 );
        arr4[ 2 ] = new Square( 2.0 );
        arr4[ 3 ] = new Square( 4.0 );
        arr4[ 4 ] = new Rectangle( 1.0, 15.0 );
        arr4[ 5 ] = new Rectangle( 4.0, 3.0 );
        
        printAll( arr4 );
        System.out.println( "Total area is " + totalArea( arr4 ) );
        
    }
}