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())
for _ in range(t):
    n=int(input())
    b=[int(x) for x in input().split()]
    
    v=set(list(range(1,2*n+1)))
    for x in b:
        v.remove(x)
    l=list(v)
    l.sort()
    ans=[-1 for _a in range(2*n)]
    ok=True
    for i in range(n):
        ans[2*i]=b[i]
        ok=False
        for j in range(len(l)):
            if l[j]>b[i]:
                ans[2*i+1]=l[j]
                l.pop(j)
                ok=True
                break
        if ok==False:
            break #impossible. could not find larger number
    if ok==False:
        print(-1)
    else:
        print(' '.join([str(x) for x in ans]))