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

public class tr2 {
	static PrintWriter out;
	static StringBuilder sb;
	static long inf = (long) 1e10;
	static ArrayList<Integer> primes;
	static ArrayList<Integer>[] ad;
	static int[] si;
	static long mod = (long) 998244353;
	static long num = (long) 1e9 + 7;
	static long[][] memo;
	static int n;
	static long k;
	static double m;
	static int[] a;
	static char[] s;
	static TreeSet<Integer> pr;
	static ArrayList<Integer> factors, times;
	static TreeSet<Integer> taken, ans;
	static TreeMap<pair1, Integer> edge;
	static boolean[] vis;

	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		out = new PrintWriter(System.out);
		int t=sc.nextInt();
		while(t-->0) {
			int n=sc.nextInt();
			int np=n*2;
			TreeSet<Integer> ts=new TreeSet<>();
			for(int i=1;i<=np;i++)
				ts.add(i);
			int []a=new int [n];
			boolean f=true;
			for(int i=0;i<n;i++) {
				a[i]=sc.nextInt();
				if(!ts.contains(a[i])) {
					f=false;
					break;
				}
				ts.remove(a[i]);
			}
			int []ans=new int [np];
			int id=0;
			for(int i=0;i<n;i++) {
				if(ts.ceiling(a[i])==null) {
					f=false;
					break;
				}
				int x=ts.ceiling(a[i]);
				ans[id++]=a[i];
				ans[id++]=x;
				ts.remove(x);
			}
			if(f) {
				for(int i=0;i<np;i++)
					out.print(ans[i]+" ");
				out.println();
			}
			else
				out.println(-1);
		}
		out.flush();
	}

	public static class pair1 implements Comparable<pair1> {
		int x;
		int y;

		pair1(int a, int i) {
			x = a;
			y = i;
			// id = g;
		}

		public String toString() {
			return x + " " + y;
		}

		@Override
		public int compareTo(pair1 o) {
			if (x == o.x)
				return y - o.y;
			return x - o.x;
		}
	}

	static long inver(long x) {
		long a = x;
		long e = (mod - 2);
		long res = 1;
		while (e > 0) {
			if ((e & 1) == 1) {
				res = ((1l * res * a) % mod);
			}
			a = (int) ((1l * a * a) % mod);
			e >>= 1;
		}
		return res % mod;
	}

	static class eq implements Comparable<eq> {
		int x;
		int y;
		long z;

		eq(int x, int y, long z) {
			this.x = x;
			this.y = y;
			this.z = z;
		}

		public String toString() {
			return x + " " + y + " " + z;
		}

		@Override
		public int compareTo(eq o) {
			if (x == o.x)
				if (o.y == y)
					return Long.compare(z, o.z);
				else
					return y - o.y;
			else
				return x - o.x;
		}
	}

	static void seive() {
		si = new int[1000001];
		primes = new ArrayList<>();
		int N = 1000001;
		si[1] = 1;
		for (int i = 2; i < N; i++) {
			if (si[i] == 0) {
				si[i] = i;
				primes.add(i);
				pr.add(i);
			}
			for (int j = 0; j < primes.size() && primes.get(j) <= si[i] && (i * primes.get(j)) < N; j++)
				si[primes.get(j) * i] = primes.get(j);

		}
	}

	static long fac(int n) {
		if (n == 0)
			return 1;
		if (n == 1)
			return 1;
		long ans = 1;
		for (int i = 1; i <= n; i++)
			ans = (i % mod * ans % mod) % mod;
		return ans % mod;
	}

	static int gcd(int a, int b) {

		if (b == 0) {
			return a;
		}
		return gcd(b, a % b);
	}

	static class pair implements Comparable<pair> {
		int num;
		int v;

		pair(int n, int v) {
			num = n;
			this.v = v;
		}

		public String toString() {
			return num + " " + v;
		}

		public int compareTo(pair o) {
			return o.v - v;
		}
	}

	static class unionfind {
		int[] p;
		int[] size;

		unionfind(int n) {
			p = new int[n];
			size = new int[n];

			for (int i = 0; i < n; i++) {
				p[i] = i;
			}
			Arrays.fill(size, 1);
		}

		int findSet(int v) {
			if (v == p[v])
				return v;
			return p[v] = findSet(p[v]);
		}

		boolean sameSet(int a, int b) {
			a = findSet(a);
			b = findSet(b);
			if (a == b)
				return true;
			return false;
		}

		int max() {
			int max = 0;
			for (int i = 0; i < size.length; i++)
				if (size[i] > max)
					max = size[i];
			return max;
		}

		void combine(int a, int b) {
			a = findSet(a);
			b = findSet(b);
			if (a == b)
				return;
			if (size[a] > size[b]) {
				p[b] = a;
				size[a] += size[b];

			} else {
				p[a] = b;
				size[b] += size[a];
			}
		}
	}

	static class Scanner {
		StringTokenizer st;
		BufferedReader br;

		public Scanner(InputStream system) {
			br = new BufferedReader(new InputStreamReader(system));
		}

		public Scanner(String file) throws Exception {
			br = new BufferedReader(new FileReader(file));
		}

		public String next() throws IOException {
			while (st == null || !st.hasMoreTokens())
				st = new StringTokenizer(br.readLine());
			return st.nextToken();
		}

		public String nextLine() throws IOException {
			return br.readLine();
		}

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

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

		public char nextChar() throws IOException {
			return next().charAt(0);
		}

		public Long nextLong() throws IOException {
			return Long.parseLong(next());
		}

		public boolean ready() throws IOException {
			return br.ready();
		}

		public void waitForInput() throws InterruptedException {
			Thread.sleep(3000);
		}
	}
}