class BankAccount:
    # BankAccount(string, integer, number)
    def __init__(self, owner, accountNumber, balance):
        self.owner = owner
        self.accountNumber = accountNumber
        self.balance = balance

    # __str__: -> string
    def __str__(self):
        return self.owner + ": #" + str(self.accountNumber) + ": $" + str(self.balance)

    # getOwner: -> string
    def getOwner(self):
        return self.owner
    # getAccountNumber: -> integer
    def getAccountNumber(self):
        return self.accountNumber
    # getBalance: -> number
    def getBalance(self):
        return self.balance

    # setOwner: string -> void
    def setOwner(self, owner):
        if (owner.strip() != ''):
            self.owner = owner
        else:
            print("Error: can't set the owner to an empty string.")
            
    # setAccountNumber: integer -> void
    def setAccountNumber(self, accountNo):
        if (accountNo >= 0):
            self.accountNumber = accountNo
        else:
            print("Error: the account number cannot be negative.")
            
    # setBalance: number -> void
    def setBalance(self, balance):
        if (balance >= 0):
            self.balance = balance
        else:
            print("Error: the balance cannot be negative.")

    # withdraw: number -> void
    def withdraw(self, amount):
        if (amount >= 0.0):
            if (self.balance >= amount):
                self.balance = self.balance - amount
            else:
                print("Error: not enough balance.")
        else:
            print("Error: cannot withdraw a negative amount.")

    # deposit: number -> void
    def deposit(self, amount):
        if (amount >= 0.0):
            self.balance = self.balance + amount
        else:
            print("Error: cannot deposit a negative amount.")