class DepositAccountB extends AccountB
{
 private boolean newmonth=true;
 private double interest;

 public DepositAccountB(int sum,double interest)
 {
  super(sum);
  this.interest=interest;
 }

 public void withdraw(int sum) throws AccountException
 {
  if(!newmonth)
     throw new AccountException("doubleWithdraw");
  else 
     {
      super.withdraw(sum);
      newmonth=false;
     }
 }

 public void update()
 {
  deposit((int)(balance()*interest));
  newmonth=true;
 }

 public void setInterest(double newInterest)
 {
  interest=newInterest;
 }
}