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:
# cook your dish here
n=int(input())
while(n):
    n=n-1
    a=int(input())
    b=list(map(int,input().split()))
    c=[True for x in range(2*a+1)]
    for x in b:
        c[x]=False
    ans=[]
    get=True
    for i in range(a):
        flag=False
        k=b[i]
        while(k<2*a+1):
            if c[k]==True:
                flag=True
                c[k]=False
                ans.append(b[i])
                ans.append(k)
                break
            else:
                k+=1
        if flag==False:
            get=False
            break
    if get:
        for x in ans:
            print(x,end=" ")
        print("\n",end="")
    else:
        print("-1")