class Account
{
 private int amount;

 public Account()
 {
  amount = 0;
 }

 public Account(int sum)
 {
  amount=sum;
 }

 public void deposit(int sum)
 {
  amount+=sum;
 }

 public boolean withdraw(int sum)
 {
  if(sum<=amount)
     {
      amount-=sum;
      return true;
     }
  else
     return false;
 }

 public int balance()
 {
  return amount;
 }
}