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:
t = int(input())
while t:
    t -= 1
    n = int(input())
    vis = [False] * (2 * n)
    ans = [-1] * (2 * n)
    b = list(map(int, input().split()))

    def check():
        global vis
        for i in b:
            if vis[i - 1] is False:
                vis[i - 1] = True
            else:
                return False
        return True

    if check() is False:
        print(-1)
        continue

    def solve():
        global ans, vis
        for i in range(0, 2 * n, 2):
            j = i // 2
            ans[i] = b[j]
            for k in range(b[j] + 1, 2 * n + 1):
                if vis[k - 1] is False:
                    vis[k - 1] = True
                    ans[i + 1] = k
                    break
            if ans[i + 1] == -1:
                return False
        return True

    if solve() is False:
        print(-1)
        continue
    else:
        print(*ans)