Question 5. (15 points) Consider the following modification of algorithm Mergesort. The algorithm first divides the input array A[low..high) into four parts A1,A2,A3, and A4 instead of two. It then sorts each part recursively, and finally merges the four sorted parts to obtain the original array in sorted order. Assume for simplicity that n is a power of 4. Analyze the modified Mergesort algorithm's running time