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:
# from collections import deque
import sys
input = lambda: sys.stdin.readline().strip()
for i in range(int(input())):
    n = int(input())
    b = list(map(int,input().split()))
    q = [i+1 for i in range(2*n)]
    used = set(b)
    j = 0
    a = [0]*2*n
    f = True
    for i in range(n):
        a[2*i]=b[i]
    for i in range(n):
        for j in q[b[i]-1:]:
            if j not in used:
                used.add(j)
                a[2*i+1]=j
                break
        if a[2*i+1]==0:
            f = False
            break
    if not f:
        print(-1)
        continue
    else:
        print(' '.join(map(str,a)))