input: Write a python function to calculate the number of combinations that can be made from a given list using a recursive approach.
  assert calculate_combinations([1, 2, 3]) == 6
  assert calculate_combinations([1, 2]) == 2
  assert calculate_combinations([1, 2, 3, 4]) == 24
output: def calculate_combinations(lst):
      def factorial(n):
          if n == 0:
              return 1
          else:
              return n * factorial(n - 1)
      
      return factorial(len(lst))