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 JAVA):

Solution:
//package codeforces.div2C;

import java.io.*;
import java.util.*;

//Think through the entire logic before jump into coding!
//If you are out of ideas, take a guess! It is better than doing nothing!
//Read both C and D, it is possible that D is easier than C for you!

//Be aware of integer overflow!
//If you find an answer and want to return immediately, don't forget to flush before return!

public class C1315 {
    static InputReader in;
    static PrintWriter out;

    public static void main(String[] args) {
        //initReaderPrinter(true);
        initReaderPrinter(false);
        solve(in.nextInt());
        //solve(1);        
    }

    static void solve(int testCnt) {
        for (int testNumber = 0; testNumber < testCnt; testNumber++) {
            int n = in.nextInt();
            int[] b = new int[n + 1];
            boolean[] used = new boolean[n * 2 + 1];
            boolean exist = true;
            for(int i = 1; i <= n; i++) {
                int v = in.nextInt();
                if(used[v]) {
                    exist = false;
                }
                used[v] = true;
                b[i] = v;
            }
            int[] ans = new int[n * 2 + 1];
            if(exist) {
                for(int i = 1; i <= n; i++) {
                    ans[i * 2 - 1] = b[i];
                }
                TreeSet<Integer> ts = new TreeSet<>();
                for(int v = 1; v <= n * 2; v++) {
                    if(!used[v]) ts.add(v);
                }
                for(int i = 2; i <= n * 2; i += 2) {
                    Integer v = ts.higher(ans[i - 1]);
                    if(v == null) {
                        exist = false;
                        break;
                    }
                    ans[i] = v;
                    ts.remove(v);
                }
            }
            if(!exist) out.println(-1);
            else {
                for(int i = 1; i <= n * 2; i++) {
                    out.print(ans[i] + " ");
                }
                out.println();
            }
        }
        out.close();
    }

    static void initReaderPrinter(boolean test) {
        if (test) {
            try {
                in = new InputReader(new FileInputStream("src/input.in"));
                out = new PrintWriter(new FileOutputStream("src/output.out"));
            } catch (IOException e) {
                e.printStackTrace();
            }
        } else {
            in = new InputReader(System.in);
            out = new PrintWriter(System.out);
        }
    }

    static class InputReader {
        BufferedReader br;
        StringTokenizer st;

        InputReader(InputStream stream) {
            try {
                br = new BufferedReader(new InputStreamReader(stream), 32768);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }

        Integer[] nextIntArray(int n) {
            Integer[] a = new Integer[n];
            for (int i = 0; i < n; i++) a[i] = nextInt();
            return a;
        }

        int[] nextIntArrayPrimitive(int n) {
            int[] a = new int[n];
            for (int i = 0; i < n; i++) a[i] = nextInt();
            return a;
        }

        int[] nextIntArrayPrimitiveOneIndexed(int n) {
            int[] a = new int[n + 1];
            for (int i = 1; i <= n; i++) a[i] = nextInt();
            return a;
        }

        Long[] nextLongArray(int n) {
            Long[] a = new Long[n];
            for (int i = 0; i < n; i++) a[i] = nextLong();
            return a;
        }

        long[] nextLongArrayPrimitive(int n) {
            long[] a = new long[n];
            for (int i = 0; i < n; i++) a[i] = nextLong();
            return a;
        }

        long[] nextLongArrayPrimitiveOneIndexed(int n) {
            long[] a = new long[n + 1];
            for (int i = 1; i <= n; i++) a[i] = nextLong();
            return a;
        }

        String[] nextStringArray(int n) {
            String[] g = new String[n];
            for (int i = 0; i < n; i++) g[i] = next();
            return g;
        }
    }
}