B"Yarik's birthday is coming soon, and Mark decided to give him an array a of length n . Mark knows that Yarik loves bitwise operations very much, and he also has a favorite number x , so Mark wants to find the maximum number k such that it is possible to select pairs of numbers [ l_1, r_1 ], [ l_2, r_2 ], ldots [ l_k, r_k ], such that: If such k does not exist, then output -1 . Each test consists of multiple test cases. The first line contains a single integer t ( 1 <= t <= 10^4 ) -- the number of test cases. The following lines contain the descriptions of the test cases. The first line of each test case contains two integers n and x ( 1 <= n <= 10^5, 0 <= x < 2^{30} ) -- the length of the array a and the number x respectively. The second line of each test case contains n integers a_1, a_2, ldots, a_n ( 0 <= a_i < 2^{30} ) -- the array a itself. It is guaranteed that the sum of the values of n across all test cases does not exceed 10^5 . For each test case, output a single integer on a separate line -- the maximum suitable number k , and -1 if such k does not exist. In the first test case, you can take k equal to 2 and choose two segments [ 1, 1 ] and [ 2, 3 ], (1) | (2 oplus 3) = 1 . It can be shown that 2 is the maximum possible answer. In the second test case, the segments [ 1, 1 ] and [ 2, 2 ] are suitable, (1) | (1) = 1 . It is not possible to make more segments. In the third test case, it is not possible to choose 2 segments, as (1) | (3) = 3 > 2 , so the optimal answer is 1 . "...