B'You are given an array a of length 2n , consisting of each integer from 1 to n exactly twice. You are also given an integer k ( 1 <= q k <= q lfloor frac{n}{2} rfloor ). You need to find two arrays l and r each of length mathbf{2k} such that: It can be proved that at least one pair of l and r always exists. If there are multiple solutions, you may output any one of them. ^ dagger A sequence x is a subset of a sequence y if x can be obtained by deleting several (possibly none or all) elements of y and rearranging the elements in any order. For example, [3,1,2,1] , [1, 2, 3] , [1, 1] and [3, 2] are subsets of [1, 1, 2, 3] but [4] and [2, 2] are not subsets of [1, 1, 2, 3] . Each test contains multiple test cases. The first line contains a single integer t ( 1 <= q t <= q 5000 ) -- the number of test cases. The description of the test cases follows. The first line of each test case contains 2 integers n and k ( 2 <= n <= 5 cdot 10^4 , 1 <= q k <= q lfloor frac{n}{2} rfloor ). The second line contains 2n integers a_1, a_2, ldots, a_{2n} ( 1 <= a_i <= n ). It is guaranteed that every integer from 1 to n occurs exactly twice in a . It is guaranteed that the sum of n over all test cases does not exceed 5 cdot 10^4 . For each test case, output two lines. On the first line of output, output 2k integers l_1, l_2, ldots, l_{2k} . On the second line of output, output 2k integers r_1, r_2, ldots r_{2k} . If there are multiple solutions, you may output any one of them. In the first test case, we choose l=[2,1] and r=[2,1] . [2, 1] is a subset of [a_1, a_2] and [2, 1] is a subset of [a_3, a_4] , and 2 oplus 1 = 2 oplus 1 = 3 . In the second test case, 6 oplus 4 = 1 op'...