B"You are given a sequence b_1, b_2, ldots, b_n . Find the lexicographically minimal permutation a_1, a_2, ldots, a_{2n} such that b_i = min(a_{2i-1}, a_{2i}) , or determine that it is impossible. Each test contains one or more test cases. The first line contains the number of test cases t ( 1 <= t <= 100 ). The first line of each test case consists of one integer n -- the number of elements in the sequence b ( 1 <= n <= 100 ). The second line of each test case consists of n different integers b_1, ldots, b_n -- elements of the sequence b ( 1 <= b_i <= 2n ). It is guaranteed that the sum of n by all test cases doesn't exceed 100 . For each test case, if there is no appropriate permutation, print one number -1 . Otherwise, print 2n integers a_1, ldots, a_{2n} -- required lexicographically minimal permutation of numbers from 1 to 2n . "...