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())
    b = list(map(int, input().split()))
    a = [0 for i in range(2*n)]
    for i in range(n):
        a[2*i] = b[i]

    rec = {}
    # for i in range(n):
    #     rec[b[i]] = i
    avail = [1 for i in range(1, 2*n + 1)]
    for i in b:
        avail[i - 1] = 0
    glob = 1
    for i in range(n):
        pos = 2*i + 1
        flag = 0
        for j in range(a[2*i], 2*n):
            if avail[j] == 1:
                flag = 1
                a[pos] = j + 1
                avail[j] = 0
                break
        if flag == 0:
            glob = 0
            break
    if glob == 0:
        print(-1)
    else:
        for i in a:
            print(i, end=' ')
        print('')