class BankingSystem:
    def __init__(self):
        # Initialize a dictionary to store account balance
        self.accounts = {}

    def create_account(self, timestamp, account_id):
        # Check if account already exists
        if account_id in self.accounts:
            return "false"
        else:
            # Create account with a balance of 0
            self.accounts[account_id] = 0
            return "true"

    def deposit(self, timestamp, account_id, amount):
        # Check if account exists
        if account_id not in self.accounts:
            return ""
        else:
            # Add amount to account balance
            self.accounts[account_id] += amount
            return str(self.accounts[account_id])

    def pay(self, timestamp, account_id, amount):
        # Check if account exists and has enough balance
        if account_id not in self.accounts or self.accounts[account_id] < amount:
            return ""
        else:
            # Subtract amount from account balance
            self.accounts[account_id] -= amount
            return str(self.accounts[account_id])

    def process_queries(self, queries):
        # Process each query and store the results
        results = []
        for query in queries:
            operation = query[0]
            if operation == "CREATE_ACCOUNT":
                result = self.create_account(query[1], query[2])
            elif operation == "DEPOSIT":
                result = self deposit(query[1], query[2], int(query[3]))
            elif operation == "PAY":
                result = self.pay(query[1], query[2], int(query[3]))
            results.append(result)
        return results

# Example queries, this should be replaced with the actual input
example_queries = [
    ["CREATE_ACCOUNT", "1", "account1"],
    ["CREATE_ACCOUNT", "2", "account1"],
    ["DEPOSIT", "3", "account1", "2700"],
    ["DEPOSIT", "4", "non-existing", "2700"],
    ["PAY", "5", "account1", "700"],
    ["PAY", "6", "non-existing", "2700"],
    ["PAY", "7", "account1", "2701"],
    ["PAY", "8", "account1", "2000"]
]

# Create a banking