"""
Recursive function to compute large exponents fast.
Rather than computing n multiplications of x, we 
recursively half the exponent, effectively creating
O(log n) time complexity.
"""
	
def power(x, n):
	if n == 1:
		return x
	elif n%2 == 0:
		return power(x**2, n/2)
	else:
		return x*power(x**2, (n-1)/2)