CF1315C Restoring Permutation

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 \le t \le 100 $ ). The first line of each test case consists of one integer $ n $ — the number of elements in the sequence $ b $ ( $ 1 \le n \le 100 $ ). The second line of each test case consists of $ n $ different integers $ b_1, \ldots, b_n $ — elements of the sequence $ b $ ( $ 1 \le b_i \le 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 $ .