2. (8 pts) In some applications (such as cryptography), we need to use very long integers. These integers cannot be stored in an int type variable. So we must use an array A[1..n] to represent such long integers. (For simplicity, each element in A is used for 1 digit, and A[n] is the most significant digit.) (For example, in the Crypto++ library widely used in cryptography applications, a special class is defined for such integers.) The basic arithmetic operations for such long integers can no longer be computed in constant time. Let A[1..n] and B[1..n] be two n-digit integers. It is easy to see the sum of A and B can be computed in (n) time. The multiplication procedure (you learned from elementary school) takes (n2) time. Describe an algorithm for multiplication, with O(nlog23)=O(n1.585) run time. (The algorithm is similar to Strassen's algorithm in nature. But much simpler.)