class Pond {
    double radius; // meter
    
    Pond( double r ) { 
        this.radius = r; 
    }
    
    double getArea() {
        return Math.PI * this.radius * this.radius;
    }
}

class Garden {
    double length; // meter
    double width;  // meter
    Pond pond;
    
    // include a default constructor to avoid problems
    Garden( ) {
     length = 0;
     width = 0;
    } 
    
    Garden( double len, double wid ) {
        this.length = len;
        this.width = wid;
    }
    
    Garden( double len, double wid, double pr ) {
        this.length = len;
        this.width = wid;
        this.pond = new Pond( pr );
    }
    
    double calcTax() {
        double tax = 0;
        if ( this.pond != null) {
            tax = this.pond.getArea() * 10;
        }
        tax = tax + this.width * this.length * 5;
        return tax;
    }
}

class MarketGarden extends Garden {
    String[] crops;
    
    MarketGarden(double len, double wid, String[] cr) {
        this.length = len;
        this.width = wid;
        this.crops = cr;
    }
    
    void printCrops() {
        for (String c : crops) {
            System.out.println( c );
        }
    }
    
    // @override
    double calcTax() {
        return this.width * this.length * 4 + crops.length * 10;
    }
}       





class Dorknoper {
    Garden g;
    Garden h;
    
    void doTax() {  
        double tax1;
        
        this.g = new Garden(12, 10, 2);
        this.h = new MarketGarden( 20, 7, new String[]{"lettuce", "carrots"} );
        
        tax1 = this.g.calcTax();
        System.out.println("belasting tuin 1: "+ tax1);
        System.out.println("belasting tuin 2: "+ 
            this.h.calcTax() );
    }
    
    public static void main(String[] args) {
        new Dorknoper().doTax();
    }
}