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 a in range(n):
    answer = ""
    size = int(input())
    nums = list(map(int,input().split()))
    taken = set(nums)
    possible = True
    if 1 not in taken:
        print(-1)
        continue
    for num in nums:
        answer += str(num) + " "
        found = False
        for b in range(num+1,2*size+1):
            if b not in taken:
                found = True
                taken.add(b)
                answer += str(b) + " "
                break
        if not found:
            possible = False
            break
    if possible:
        print(answer)
    else:
        print(-1)