input: from typing import List
  
  
  def is_balance_negative(operations: List[int]) -> bool:
      """ Provided a series of deposit and withdrawal transactions on a zero-initialized bank account.
      The function should return True if the account balance goes negative at any time. If it remains
      non-negative, the function should return False.
      >>> is_balance_negative([1, 2, 3])
      False
      >>> is_balance_negative([1, 2, -4, 5])
      True
      """
output:     balance = 0
      for operation in operations:
          balance += operation
          if balance < 0:
              return True
      return False