def fib_1_recursive(n):
	"""
	Solution: Brute force recursive solution.
	Complexity:
		Description: Number of computations can be represented as a binary
		tree has height of n.
		Time: O(2^n)
	"""
	if n < 0:
		raise ValueError('input must be a positive whole number')

	if n in [0, 1]:
		return n

	return fib_1_recursive(n - 2) + fib_1_recursive(n - 1)