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;
const int MAX = 200005;
int a[MAX];
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    bool flag = false;
    int maxc = n * 2;
    bool b[205];
    memset(b, false, sizeof(b));
    for (int i = 0; i < n; i++) {
      cin >> a[i];
      b[a[i]] = true;
      if (a[i] == maxc) {
        flag = true;
      }
    }
    if (flag) {
      cout << -1 << endl;
      continue;
    }
    vector<int> ans;
    for (int i = 0; i < n; i++) {
      for (int j = 1; j <= 2 * n; j++) {
        if (b[j] == false) {
          if (a[i] < j) {
            b[j] = true;
            ans.push_back(a[i]);
            ans.push_back(j);
            break;
          }
        }
      }
    }
    if (ans.size() != 2 * n) {
      cout << -1 << endl;
    } else {
      for (auto &q : ans) {
        cout << q << " ";
      }
      cout << endl;
    }
  }
  return 0;
}