4. (8 pts) Let F(n) be a function defined on the integers {1,2,,n}.F(n) is said bitonic if its values first strictly increasing, then strictly decreasing. F(k) is the maximum value of F if F(k)>F(i) for any i(1in and i=k).F(i) can be computed by calling a procedure F(i). We need to compute the maximum value F(k). This can easily done by calling F(i)n times and keep the maximum value. However, the calling of F(i) takes a long time. Describe an algorithm that finds the maximum value F(k) and evaluates F(i) at most O(logn) times