Problem: You are given a sequence b_1, b_2, …, b_n. Find the lexicographically minimal permutation a_1, a_2, …, a_{2n} such that b_i = min(a_{2i-1}, a_{2i}), or determine that it is impossible.

Input

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, …, 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.

Output

For each test case, if there is no appropriate permutation, print one number -1.

Otherwise, print 2n integers a_1, …, a_{2n} — required lexicographically minimal permutation of numbers from 1 to 2n.

Example

Input


5
1
1
2
4 1
3
4 1 3
4
2 3 4 5
5
1 5 7 2 8


Output


1 2 
-1
4 5 1 2 3 6 
-1
1 3 5 6 7 9 2 4 8 10 

Solution (in PYTHON3):

Solution:
if __name__ == '__main__':
    t = int(input())
    for _ in range(t):
        n = int(input())
        l = [int(i) for i in input().split(' ')]
        res = []
        a = sorted(list(set([i for i in range(1, 2 * n + 1)]) - set(l)))
        # print(l)
        # print(a)

        for i in range(n):
            cur = l[i]
            for j in a:
                if j > cur:
                    res.append(cur)
                    res.append(j)
                    a.remove(j)
                    break
        # print(res)
        if len(res) == n * 2:
            print(' '.join([str(i) for i in res]))
        else:
            print(-1)