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.util.*;
import java.io.*;
import java.math.*;
public class C623{
    public static int lower(ArrayList<Integer> a,int x){
        int low=0;
        int high=a.size();
        while(low<high){
            int mid=(low+high)/2;
            if(x<=a.get(mid))
                high=mid;
            else 
                low=mid+1;
        }
        return low;
    }

	public static void main(String args[]){
		FastReader sc = new FastReader();
        int t,n,i;
        t=sc.nextInt();
        while(t-->0){
            n=sc.nextInt();
            int b[]=new int[n+1];
            int a[]=new int[2*n+1];
            int f[]=new int[2*n+1];
            Arrays.fill(f,1);
            for(i=1;i<=n;i++){
                b[i]=sc.nextInt();
                a[2*i-1]=b[i];
                f[b[i]]--;
            }
            int flag=1;
            ArrayList<Integer> sch=new ArrayList<>();
            for(i=1;i<=2*n;i++){
                if(f[i]==1)
                    sch.add(i);
            }
            //out.println(sch);
            for(i=2;i<=2*n;i+=2){
                int idx=lower(sch,a[i-1]);
                if(idx==sch.size()){
                    flag=0;
                    break;
                }
                else{
                    a[i]=sch.get(idx);
                    sch.remove(idx);
                }
            }
            if(flag==0){
                out.println(-1);
                continue;
            }
            for(i=1;i<=2*n;i++)
                out.print(a[i]+" ");
            out.println();
            
        }
		out.flush();
	}

	static PrintWriter out;
	static class FastReader{
		BufferedReader br;
		StringTokenizer st;
		public FastReader(){
			br=new BufferedReader(new InputStreamReader(System.in));
			out=new PrintWriter(System.out);
		}
		String next(){
			while(st==null || !st.hasMoreElements()){
				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;
		}
	}

	public static boolean isPrime(int n) {
		if(n<2) return false;
		for(int i=2;i<=(int)Math.sqrt(n);i++) {
			if(n%i==0) return false;
		}
		return true;
	}

	public static void print(int a[],int l,int r){
		int i;
		for(i=l;i<=r;i++)
			out.print(a[i]+" ");
		out.println();
	}

	public static long fastexpo(long x, long y, long p){
		long res=1;
		while(y > 0){
			if((y & 1)==1)
				res= ((res%p)*(x%p))%p;
			y= y >> 1;			
			x = ((x%p)*(x%p))%p;
		}
		return res;
	}

	public static boolean[] sieve (int n) {
		boolean primes[]=new boolean[n+1];
		Arrays.fill(primes,true);
		primes[0]=primes[1]=false;
		for(int i=2;i*i<=n;i++){
			if(primes[i]){
				for(int j=i*i;j<=n;j+=i)
					primes[j]=false;
			}
		}
		return primes;
	}

	public static long gcd(long a,long b){
        return (BigInteger.valueOf(a).gcd(BigInteger.valueOf(b))).longValue();
    }

    public static void merge(int a[],int l,int m,int r){
        int n1,n2,i,j,k;
        n1=m-l+1;
        n2=r-m;

        int L[]=new int[n1];
        int R[]=new int[n2];

        for(i=0;i<n1;i++)
            L[i]=a[l+i];
        for(j=0;j<n2;j++)
            R[j]=a[m+1+j];

        i=0;j=0;

        k=l;
        while(i<n1&&j<n2){
            if(L[i]<=R[j]){
                a[k]=L[i];
                i++;
            }
            else{
                a[k]=R[j];
                j++;
            }
            k++;
        }

        while(i<n1){
            a[k]=L[i];
            i++;
            k++;
        }
        while(j<n2){
            a[k]=R[j];
            j++;
            k++;
        }
    }
    public static void sort(int a[],int l,int r){
        int m;
        if(l<r){
            m=(l+r)/2;
            sort(a,l,m);
            sort(a,m+1,r);
            merge(a,l,m,r);
        }
    }
}