class ATMSimulation:
    def __init__(self):
        # Dictionary to store account details {account_number: {"pin": ..., "balance": ...}}
        self.accounts = {}

    def create_account(self, account_number, pin, initial_balance=0):
        """Create a new account."""
        if account_number in self.accounts:
            print("Account already exists.")
        else:
            self.accounts[account_number] = {"pin": pin, "balance": initial_balance}
            print(f"Account {account_number} created successfully with balance {initial_balance}.")

    def validate_account(self, account_number, pin):
        """Validate account number and PIN."""
        if account_number in self.accounts and self.accounts[account_number]["pin"] == pin:
            return True
        return False

    def balance_inquiry(self, account_number):
        """Check account balance."""
        print(f"Current balance: {self.accounts[account_number]['balance']}")

    def deposit(self, account_number, amount):
        """Deposit money into the account."""
        if amount > 0:
            self.accounts[account_number]["balance"] += amount
            print(f"Deposited {amount}. New balance: {self.accounts[account_number]['balance']}")
        else:
            print("Invalid deposit amount. Please enter a positive value.")

    def withdraw(self, account_number, amount):
        """Withdraw money from the account."""
        if 0 < amount <= self.accounts[account_number]["balance"]:
            self.accounts[account_number]["balance"] -= amount
            print(f"Withdrawn {amount}. Remaining balance: {self.accounts[account_number]['balance']}")
        elif amount > self.accounts[account_number]["balance"]:
            print("Insufficient balance.")
        else:
            print("Invalid withdrawal amount. Please enter a positive value.")

    def main_menu(self):
        """Display the main menu."""
        while True:
            print("\n--- ATM Simulation ---")
            print("1. Create Account")
            print("2. Login to Account")
            print("3. Exit")
            choice = input("Enter your choice: ")
            if choice == "1":
                self.create_account_menu()
            elif choice == "2":
                self.account_menu()
            elif choice == "3":
                print("Thank you for using the ATM. Goodbye!")
                break
            else:
                print("Invalid choice. Please try again.")

    def create_account_menu(self):
        """Menu for creating a new account."""
        account_number = input("Enter a new account number: ")
        pin = input("Set a 4-digit PIN: ")
        while len(pin) != 4 or not pin.isdigit():
            print("PIN must be a 4-digit number. Please try again.")
            pin = input("Set a 4-digit PIN: ")

        initial_balance = input("Enter an initial deposit amount (or leave empty for 0): ")
        initial_balance = float(initial_balance) if initial_balance.strip() else 0
        self.create_account(account_number, pin, initial_balance)

    def account_menu(self):
        """Menu for logged-in account operations."""
        account_number = input("Enter your account number: ")
        pin = input("Enter your PIN: ")
        if self.validate_account(account_number, pin):
            print("Login successful!")
            while True:
                print("\n--- Account Menu ---")
                print("1. Balance Inquiry")
                print("2. Deposit")
                print("3. Withdraw")
                print("4. Logout")
                choice = input("Enter your choice: ")
                if choice == "1":
                    self.balance_inquiry(account_number)
                elif choice == "2":
                    try:
                        amount = float(input("Enter amount to deposit: "))
                        self.deposit(account_number, amount)
                    except ValueError:
                        print("Invalid amount. Please enter a numeric value.")
                elif choice == "3":
                    try:
                        amount = float(input("Enter amount to withdraw: "))
                        self.withdraw(account_number, amount)
                    except ValueError:
                        print("Invalid amount. Please enter a numeric value.")
                elif choice == "4":
                    print("Logged out successfully.")
                    break
                else:
                    print("Invalid choice. Please try again.")
        else:
            print("Invalid account number or PIN.")


# Run the ATM Simulation
atm = ATMSimulation()
atm.main_menu()