def factRecur(num):
	"""
	Calculates the factorial of a given natural number recursively.

    Keyword arguments:
    num -- the natural number
    """
	def factRecurAux(acc,num):
		if num == 1:
			return acc
		else:
			return factRecurAux(acc*num, num-1)
	if num == 0:
		return 1
	else:
		return factRecurAux(1,num)