public abstract class Income {
    protected double income;
    public Income(double income) {
        this.income = income;
    }
    public abstract double getTax ();
	// TODO

}

public class RoyaltyIncome extends Income {
    public  RoyaltyIncome (double income) {
        super(income);
    }
    @Override
    public double getTax() {
        return income*0.2;
    }


	// TODO

}

public class SalaryIncome extends Income {
    public SalaryIncome(double income) {
        super(income);
    }
    @Override
    public double getTax() {
        double b = 0;
        if (income<5000){
            b = 0;
        } else if(income>=5000) {
           b= (income-5000)*0.2;
        }
        return b;
    }
}

public class Main {

	public static void main(String[] args) {
		// TODO: 用抽象类给一个有工资收入和稿费收入的小伙伴算税:
		Income[] incomes = new Income[] { new SalaryIncome(7500), new RoyaltyIncome(12000) };
		double total = 0;
		for (Income ic:
			 incomes) {
			total = total +ic.getTax();
		}

		// TODO:
		System.out.println(total);
	}

}