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())
test_cases = [(input(),input()) for i in range(t)]

def solve(test_case):
    n = int(test_case[0])
    b = list(map(int,test_case[1].split()))

    c = [i for i in range(1,2*n+1) if i not in b]
    a = []

    for i in range(n):
        a.append(b[i])
        if c[-1] > b[i]:
            tmp = min([c[j] for j in range(len(c)) if c[j] > b[i]])
            a.append(tmp)
            c.remove(tmp)
        else:
            print(-1)
            return

    print(' '.join(map(str,a)))

for test_case in test_cases:
    solve(test_case)