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:
n = int(input())

for i in range(n):
    lena = int(input())
    arr = list(map(int, input().split()))
    rem = [j for j in list(range(1, 2*lena+1)) if j not in arr]
    counter = 0
    final = []

    for j in range(lena):
        counter2 = 0
        for k in range(arr[j], 2*lena+1):
            if k in rem:
                final.append(arr[j])
                final.append(k)
                rem.remove(k)
                counter2 = 1
                break
        if counter2 == 0:
            print(-1)
            counter = 1
            break

    if counter == 0:
        print(*final)