You may assume that $n$ is a power of two. We have n input keys that form a reverse sorted sequence for example < n , n-1, ... , 3 , 2 ,1 >. We run MergeSort on that input. Find a tight upper bound that describes the number of comparisons performed by MergeSort on that input. If the upper bound is of the form (A/B) n lgn + Cn +D where, A = ?, B=? , C= ? , D = ?