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 i in range(0,t):
    n=int(input())
    b=[]
    c=[]
    a=list(map(int,input().split()))
    k1=1
    k2=n*2
    if(k1 in a and k2 not in a):
        for j in range(1,2*n+1):
            if(j not in a):
                b.append(j)
        for j in range(0,n):
            k=a[j]+1
            f=1
            while(k not in b):
                k=k+1
                if(k>2*n):
                    f=0
                    break
            if(f==0):
                print(-1)
                break
            c.append(a[j])
            c.append(k)
            b.pop(b.index(k))
        if(f==0):
            continue
        for j in range(0,2*n):
            print(c[j],end=" ")
        print("")
        
    else:
        print(-1)