You are given a binary string A of length B. You have an operation where you can flip a substring of A such that 1 becomes 0 and vice-versa. You have to find out the number of ordered pairs (X, Y) such that X + Y = XAY = decimal representation of A after performing exactly 1 operations. Find out the maximum number of pairs (X, Y) after performing the operation on A. Since the answer can be large, output the answer modulo 109+7.