B"Let's call an array a_1, a_2, ... , a_m of nonnegative integer numbers good if a_1 + a_2 + ... + a_m = 2 cdot(a_1 oplus a_2 oplus ... oplus a_m) , where oplus denotes the bitwise XOR operation. For example, array [1, 2, 3, 6] is good, as 1 + 2 + 3 + 6 = 12 = 2 cdot 6 = 2 cdot (1 oplus 2 oplus 3 oplus 6) . At the same time, array [1, 2, 1, 3] isn't good, as 1 + 2 + 1 + 3 = 7 neq 2 cdot 1 = 2 cdot(1 oplus 2 oplus 1 oplus 3) . You are given an array of length n : a_1, a_2, ... , a_n . Append at most 3 elements to it to make it good. Appended elements don't have to be different. It can be shown that the solution always exists under the given constraints. If there are different solutions, you are allowed to output any of them. Note that you don't have to minimize the number of added elements!. So, if an array is good already you are allowed to not append elements. Each test contains multiple test cases. The first line contains the number of test cases t ( 1 <= t <= 10 ,000 ). The description of the test cases follows. The first line of each test case contains a single integer n (1 <= n <= 10^5) -- the size of the array. The second line of each test case contains n integers a_1, a_2, ... , a_n ( 0 <= a_i <= 10^9 ) -- the elements of the array. It is guaranteed that the sum of n over all test cases does not exceed 10^5 . For each test case, output two lines. In the first line, output a single integer s ( 0 <= s <= 3 ) -- the number of elements you want to append. In the second line, output s integers b_1, ... , b_s ( 0 <= b_i <= 10^{18} ) -- the elements you want to append to the array. If there are different solutions, you are allowed to output any of them. In the first test case of the example, the sum of all numbers is 12 , and their oplus is 6 , so the condition is already satisfied. I"...