public class Main {

public static void main(String[] args) {

Shouru[] shourus = new Shouru[] { new Income(3000), new SalaryIncome(7500), new RoyaltyIncome(12000) };

double total = 0;

for(Shouru shouru:shourus) {

total=total+shouru.getTax();

}

System.out.println(total);

}

}

interface Shouru{

double getTax();

}

class Income implements Shouru{

protected double income;

public Income(double income) {

super();

this.income=income;}

@Override

public double getTax() {

return income*0.1;

}

}

class SalaryIncome implements Shouru{

protected double income;

public SalaryIncome(double income) {

super();

this.income=income;}

@Override

public double getTax() {

if(income<5000) {return 0;}

return(income-5000)*0.2;}

}

class RoyaltyIncome implements Shouru{

protected double income;

public RoyaltyIncome(double income) {

super();

this.income=income;}

@Override

public double getTax() {

if(income<10000) {return 0;}

return(income-10000)*0.3;}

}