On a recent birthday, your best friend Maurice gave you a pair of numbers (n) and (x), and asked you to construct an array of positive numbers (a) of length (n) such that (a_1 \oplus a_2 \oplus \cdots \oplus a_n = x) (^{\text{∗}}). This task seemed too simple to you, and therefore you decided to give Maurice a return gift by constructing an array among all such arrays that has the smallest sum of its elements. You immediately thought of a suitable array; however, since writing it down turned out to be too time-consuming, Maurice will have to settle for just the sum of its elements. (^{\text{∗}})(\oplus) denotes the bitwise XOR operation . Each test contains multiple test cases. The first line contains the number of test cases (t) ((1 \le t \le 10^4)). The description of the test cases follows. Each test case consists of a single line containing a pair of numbers (n) and (x) ((1 \le n \le 10^9, \; 0 \le x \le 10^9)) — the numbers given to you by Maurice. For each test case, output your gift to Maurice — the sum of the elements of the array that satisfies all the described properties. If a suitable array does not exist, output (-1). In the first test case, one of the suitable arrays is (2, 3). It can be shown that it is impossible to achieve a smaller sum of array elements. In the second case, one of the suitable arrays is (1, 3, 4). It can also be shown that this is the optimal amount.