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:
from bisect import *
from collections import *
from itertools import *
import functools
import sys
import math
from decimal import *
from copy import *
from heapq import *
from fractions import *
getcontext().prec = 30
MAX = sys.maxsize
MAXN = int(1.5e6)
MOD = 10**9+7
spf = [i for i in range(MAXN)]
spf[0]=spf[1] = -1
def sieve():
    for i in range(2,MAXN,2):
        spf[i] = 2
    for i in range(3,int(MAXN**0.5)+1):
        if spf[i]==i:
            for j in range(i*i,MAXN,i):
                if spf[j]==j:
                    spf[j]=i
def fib(n,m):
    if n == 0:
        return [0, 1]
    else:
        a, b = fib(n // 2)
        c = ((a%m) * ((b%m) * 2 - (a%m)))%m
        d = ((a%m) * (a%m))%m + ((b)%m * (b)%m)%m
        if n % 2 == 0:
            return [c, d]
        else:
            return [d, c + d]

def charIN(x= ' '):
    return(sys.stdin.readline().strip().split(x))

def arrIN(x = ' '):
    return list(map(int,sys.stdin.readline().strip().split(x)))

def ncr(n,r):
    num=den=1
    for i in range(r):
        num = (num*(n-i))%MOD
        den = (den*(i+1))%MOD

    return (num*(pow(den,MOD-2,MOD)))%MOD

def flush():
    return sys.stdout.flush()

'''*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*'''
for _ in range(int(input())):
    n = int(input())
    b = [0]+arrIN()
    a = [0]*(2*n+1)
    if (1 not in b) or (2*n in b):
        print(-1)
        continue
    f = [1]*(2*n+1)
    for i in range(1,n+1):
        a[2*i-1] = b[i]
        f[b[i]] = 0
    rem = [i for i in range(1,2*n+1) if f[i]]
    rem.sort()
    for i in range(1,n+1):
        idx = bisect_left(rem,b[i])
        if idx==len(rem):
            print(-1)
            break
        a[2*i] = rem[idx]
        rem.pop(idx)
    else:
        print(*a[1:])