Consider the following definition of a function power which computes xn (i.e., x raised to the nth power):
(define (power x n)
(cond ((= n 0) 1)
((even? n) (power (* x x) (/ n 2))) ; recursive call #1
(else (* x (power x (- n 1)))))) ; recursive call #2
If we assume that all primitive operations used in the function (cond, =, *, odd?, -, etc.) require constant time, then determine the running time of power as a function of the magnitude of n. Use big-O notation to express your result.