input: from typing import List
  
  
  def factorial_using_recursion(n: int) -> int:
      """
      Define a recursive function to calculate the factorial of a given number.
      >>> factorial_using_recursion(5)
      120
      >>> factorial_using_recursion(1)
      1
      """
      if n == 1:
          return 1
      else:
          return n * factorial_using_recursion(n - 1)
output:     if n == 0:
          return 1