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:
for _ in range(int(input())):
    n = int(input())
    seq = list(map(int, input().split()))
    if(len(set(seq))) != n or max(seq) > 2 * n - 1:
        print(-1)
        continue
    myst = set(range(1, 2 * n + 1)) - set(seq)
    myst = list(sorted(myst))
    #fnd = list(sorted(map(lambda tp: (tp[1], tp[0]), enumerate(seq))))
    ans = []
    fl = True
    for x in seq:
        upbnd = 0
        while upbnd < len(myst) and myst[upbnd] < x:
            upbnd += 1
        if upbnd == len(myst):
            fl = False
            break
        ans.append(x)
        ans.append(myst[upbnd])
        myst.pop(upbnd)
    if not fl:
        print(-1)
    else:
        print(*ans)