input: def max_revenue(prices: List[int]) -> int:
      """ Calculates the maximum revenue that can be obtained from a list of prices.
      The function takes a list of prices and computes the maximum difference between
      any two consecutive prices, which represents the maximum revenue.
      >>> max_revenue([10, 7, 5, 8, 11, 9])
      6
      """
output:     max_diff = 0
      for i in range(len(prices) - 1):
          diff = prices[i + 1] - prices[i]
          if diff > max_diff:
              max_diff = diff
      return max_diff