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:
TC = int(input())

def get_unused(nums, res):
    unused = set(range(1, 2 * n + 1))
    for v in res:
        unused.remove(v)
    return unused


def solve(nums):
    res = []
    n = len(nums)
    extra = 10 * n
    used = [0] * (2 * n + 1)
    for num in nums:
        res.append(extra)
        res.append(num)
        used[num] = 1


    for i in range(n):
        found = False
        for j in range(nums[i] + 1, 2 * n + 1):
            if not used[j]:
                res[2 * i] = j
                used[j] = 1
                found = True
                break

        if not found:
            return []
        if res[2 * i] > res[2 * i + 1]:
            res[2 * i], res[2 * i + 1] = res[2 * i + 1], res[2 * i]

    return res

for _ in range(TC):
    n = int(input())
    *nums, = map(int, input().split())

    res = solve(nums)

    if res:
        print(*res)
    else:
        print(-1)