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:
import sys
from collections import defaultdict
def make(b):
    n=len(b)
    ans=[-1 for _ in range(2*n)]
    vis=defaultdict(int)
    for i in range(0,2*n,2):
        ans[i]=b[i//2]
        vis[b[i//2]]=1
    for i in range(1,2*n,2):
        for j in range(ans[i-1]+1,2*n+1):
            if vis[j]==0:
                ans[i]=j
                vis[j]=1
                break

        if ans[i]==-1:
            return False
    return ans
t=int(sys.stdin.readline())
for _ in range(t):
    n=int(sys.stdin.readline())
    b=list(map(int,sys.stdin.readline().split()))
    a=make(b)
    if a:
        print(*a)
    else:
        print(-1)