class BankAccount:
    def __init__(self, owner: str, balance: float):
        self.owner = owner
        self.balance = balance
    
    def deposit(self, amount: float):
        self.balance += amount
        return self.balance

    def withdraw(self, amount: float):
        if self.balance < amount:
            raise ValueError()
        self.balance -= amount
        return self.balance

    def __str__(self):
        return f"Owner: {self.owner}, Balance: {self.balance}"