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:
for tc in range(int(input())):
    n = int(input())
    b = list(map(int, input().split(' ')))
    b.insert(0, 0)
    a = (2*n+1)*[0]
    s = set()
    flag = True
    for i in range(1,n+1):
        a[2*i-1] = b[i]
        if b[i] in s:
            flag = False
            break
        s.add(b[i])
    for i in range(1,len(b)):
        val = b[i]+1
        while val in s:
            val+=1
        a[2*i] = val
        s.add(val)
    for i in range(1,2*n+1):
        if not i in s:
            flag = False
            break
    if flag:
        print(*a[1:])
    else:
        print(-1)