B"You are given an integer array a_1, a_2, ... , a_n ( 0 <= a_i <= 10^9 ). In one operation, you can choose an integer x ( 0 <= x <= 10^{18} ) and replace a_i with lfloor frac{a_i + x}{2} rfloor ( lfloor y rfloor denotes rounding y down to the nearest integer) for all i from 1 to n . Pay attention to the fact that all elements of the array are affected on each operation. Print the smallest number of operations required to make all elements of the array equal. If the number of operations is less than or equal to n , then print the chosen x for each operation. If there are multiple answers, print any of them. The first line contains a single integer t ( 1 <= t <= 10^4 ) -- the number of testcases. The first line of each testcase contains a single integer n ( 1 <= n <= 2 cdot 10^5 ). The second line contains n integers a_1, a_2, ... , a_n ( 0 <= a_i <= 10^9 ). The sum of n over all testcases doesn't exceed 2 cdot 10^5 . For each testcase, print the smallest number of operations required to make all elements of the array equal. If the number of operations is less than or equal to n , then print the chosen x for each operation in the next line. If there are multiple answers, print any of them. In the first testcase, all elements are already equal, so 0 operations are required. It doesn't matter if you print an empty line afterwards or not. In the second testcase, you can't make less than 2 operations. There are multiple answers, let's consider the answer sequence [2, 5] . After applying an operation with x = 2 , the array becomes [ lfloor frac{4 + 2}{2} rfloor, lfloor frac{6 + 2}{2} rfloor] = [3, 4] . After applying an operation with x = 5 after that, the array becomes [ lfloor frac{3 + 5}{2} rfloor, lfloor frac{4 + 5}{2} rfloor] = [4, 4] . Both elements are the same,"...