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 CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
int a[101], ac[202];
void solve() {
  int n;
  cin >> n;
  bool f = 0;
  memset(ac, 0, sizeof(ac));
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    ac[a[i]] = 1;
  }
  if (ac[1] == 0) {
    f = 1;
  }
  vector<int> v;
  for (int i = 0; i < n; i++) {
    bool k = 0;
    for (int j = a[i] + 1; j <= 2 * n; j++) {
      if (ac[j] == 0) {
        ac[j] = 1;
        k = 1;
        v.push_back(a[i]);
        v.push_back(j);
        break;
      }
    }
    if (k == 0) {
      f = 1;
      break;
    }
  }
  if (f) {
    cout << "-1\n";
    return;
  } else {
    for (int i : v) {
      cout << i << " ";
    }
  }
  cout << "\n";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long t = 1;
  cin >> t;
  while (t--) {
    solve();
  }
  return 0;
}