public class Problem1
{
   /**
      Counts how many bank accounts are overdrawn.
      @param accounts the bank accounts
      @return the number of bank accounts with a negative balance
   */
   int overdrawn(BankAccount[] accounts)
   {
      ... ... = ...;
      for (...)
      {
         if (...)
         {
            ...
         }
      }
      return ...;
   }

   /**
      Returns the bank account with the highest balance.
      @param accounts the bank accounts
      @return the bank account with the highest balance
   */
   BankAccount highestBalance(BankAccount[] accounts)
   {
      ... ... = ...;
      for (...)
      {
         if (...)
         {
            ...
         }
      }
      return ...;
   }

   /**
      ...
      @param ...
      @return ...
   */
   String mystery(BankAccount[] accounts)
   {
      String r = "";
      for (BankAccount a : accounts)
      {
         if (!r.equals("")) r = r + ", ";
         r = r + a.getBalance();
      }
      return r;
   }
}