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public class Example2_4 {
public static void main(String args[]){
int a=5??b=3;
Son son=new Son();
GrandSon sunzi=new GrandSon();
son.changeMoneyHK(666);
son.changeMoneyRMB(5000);
System.out.println(son.moneyHK);
System.out.println(son.moneyRMB);
System.out.println(son.sub(a??b));
System.out.println(son.add(a??b));
System.out.println(sunzi.moneyHK);
System.out.println(sunzi.moneyRMB);
System.out.println(sunzi.sub(a??b));
System.out.println(sunzi.add(a??b));
System.out.println(sunzi.multi(a??b));
}
}
class Father{
private int moneyDollar=300;
int moneyHK=200;
int add(int x??int y){
return x+y;
}
}
class Son extends Father{
int moneyRMB=800;
public void changeMoneyRMB(int x){
moneyRMB=x;
}
public void changeMoneyHK(int x){
moneyHK=x;
}
int sub(int x??int y){
return x-y;
}
}
class GrandSon extends Son{
int multi(int x??int y){
return x*y;
}
}

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