# Build a Banking System with Activity Rankings ## Problem Implement an in-memory banking system that processes these operations: - `CREATE_ACCOUNT account_id` - `DEPOSIT account_id amount` - `TRANSFER source_id target_id amount` - `TOP_ACTIVITY n` The operation rules are: 1. Creating a new account returns `True`; creating an existing account returns `False`. 2. A successful deposit adds `amount` to the account balance and returns the new balance. It returns `-1` if the account does not exist. 3. A successful transfer subtracts `amount` from the source, adds it to the target, and returns the source's new balance. It returns `-1` if either account is missing, the account identifiers are equal, or the source lacks funds. 4. Each account has an activity indicator. A successful deposit adds its amount to that account's activity. A successful transfer adds its amount to both participating accounts' activity. Failed operations do not affect balances or activity. 5. `TOP_ACTIVITY n` returns up to `n` strings formatted as `"account_id(activity)"`, ordered by activity descending and then account identifier ascending. If fewer than `n` accounts exist, return all of them. Implement the literal-input driver below and return one result per operation in input order. Operation arguments are strings; parse monetary amounts and `n` as integers. ```python def process_operations(operations: list[list[str]]) -> list[object]: ... ``` ## Constraints - `1 <= len(operations) <= 100_000` - Account identifiers are non-empty ASCII strings. - Deposit and transfer amounts are positive integers. - `n` is a positive integer. - Balances and activity indicators fit in signed 64-bit integers. ## Example ```python operations = [ ["CREATE_ACCOUNT", "account1"], ["CREATE_ACCOUNT", "account2"], ["DEPOSIT", "account1", "2700"], ["TRANSFER", "account1", "account2", "200"], ["TOP_ACTIVITY", "2"], ] ``` The result is: ```python [True, True, 2700, 2500, ["account1(2900)", "account2(200)"]] ```