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 = list(map(int, input().split()))
    
    if max(b) >= n*2 or 1 not in b:
        print(-1)
    else:
        a = [0]*(2*n)
        ok = True
        for i in range(n):
            a[i*2] = b[i]
            
        while 0 in a:
            moved = False
            for i in range(1, 1+2*n):
                ind = a.index(0)
                if i not in a and i > a[ind-1]:
                    a[ind] = i
                    moved = True
                    break
            
            if not moved:
                ok = False
                break
                
        if not ok:
            print(-1)
        else:
            print(*a)