public class Main{

public static void main(String[] args) {

Income[] incomes=new Income[] {new Income(6000),new Gongzi(8000),new Gaofei(15000)};

System.out.println(All(incomes));

}

public static double All(Income...incomes) {

double a=0;

for(Income income:incomes) {

a=a+income.getTax();}

return a;}

}

class Income{

protected double income;

public Income(double income) {

this.income=income;}

public double getTax() {

return income*0.1;}

}

class Gongzi extends Income{

public Gongzi(double income) {

super(income);

}

@Override

public double getTax() {

if(income<5000) {

return 0;}

return (income-5000)*0.2;}

}

class Gaofei extends Income{

public Gaofei(double income) {

super(income);}

@Override

public double getTax() {

if(income<10000) {return 0;}

return (income-10000)*0.2;}

}