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 MyClass {
    
    public static void main(String args[]) {
      FastReader sc = new FastReader();     //For Fast IO
      //func f = new func();                  //Call func for swap , permute, upper bound and for sort.
      StringBuilder sb = new StringBuilder();
      int t = sc.nextInt();
      while(t-->0){
          int n = sc.nextInt();
          int b[] = new int[n];
          int min = Integer.MAX_VALUE;
          int max = Integer.MIN_VALUE;
          for(int i=0;i<n;i++){
              b[i]=sc.nextInt();
              if(max<b[i]){
                  max=b[i];
              }
              if(min>b[i]){
                  min=b[i];
              }
          }
          if(max==2*n){
              System.out.println(-1);
              continue;
          }
          else if(min!=1){
              System.out.println(-1);
              continue;
          }
          else{
              int arr[] = new int[2*n];
              int count[] = new int[2*n+1];
              int ind=0;
              for(int i=0;i<n;i++){
                  arr[ind]=b[i];
                  count[arr[ind]]=1;
                  ind+=2;
              }
              int f=0;
              for(int i=0;i<2*n;i++){
                  if(arr[i]>0){continue;}
                  else{
                      int x = arr[i-1]+1;
                      while(x<=2*n && count[x]==1){
                          x++;
                      }
                      if(x>2*n){
                          x=1;
                          while(x<=2*n && count[x]==1){
                              x++;
                          }
                          if(x<arr[i-1]){
                              f=1;
                              break;
                          }
                          arr[i]=x;
                          count[x]=1;
                      }
                      else{
                          arr[i]=x;
                          count[x]=1;
                      }
                  }
                  
              }
              if(f==1){
                  System.out.println(-1);
                  continue;
              }
              for(int i=0;i<2*n;i++){
                  System.out.print(arr[i]+" ");
              }
              System.out.println();
          }
      }
      
      
    }
}
class Pair{
    int x;
    int y;
    Pair(int i,int j){
        x=i;
        y=j;
    }
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (!(o instanceof Pair)) return false;
        Pair key = (Pair) o;
        return x == key.x && y == key.y;
    }
    @Override
    public int hashCode() {
        int result = x;
        result = 31*result + y;
        return result;
    }
}
class FastReader 
	{ 
		BufferedReader br; 
		StringTokenizer st; 
 
		public FastReader() 
		{ 
			br = new BufferedReader(new
					InputStreamReader(System.in)); 
		} 
 
		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; 
		} 
	}
class func{
    static ArrayList<String> al = new ArrayList<>();
        public static void sort(long[] arr) {
            int n = arr.length, mid, h, s, l, i, j, k;
            long[] res = new long[n];
            for (s = 1; s < n; s <<= 1) {
                for (l = 0; l < n - 1; l += (s << 1)) {
                    h = Math.min(l + (s << 1) - 1, n - 1);
                    mid = Math.min(l + s - 1, n - 1);
                    i = l;
                    j = mid + 1;
                    k = l;
                    while (i <= mid && j <= h) res[k++] = (arr[i] <= arr[j] ? arr[i++] : arr[j++]);
                    while (i <= mid) res[k++] = arr[i++];
                    while (j <= h) res[k++] = arr[j++];
                    for (k = l; k <= h; k++) arr[k] = res[k];
                }
            }
        }
        public static void permute(char a[] , int i , int n){
            if(i==n-1){
                String s = new String(a);
                al.add(s);                      // al stores all permutations of string. 
                return;
            }
            for(int j=i;j<n;j++){
                swap(a,i,j);
                permute(a,i+1,n);
                swap(a,i,j);
            }
        }
        public static void swap(char a[],int i, int j){
            char temp = a[i];
            a[i] = a[j];
            a[j] = temp;
        }
        public static void swap(int a[],int i, int j){
            int temp = a[i];
            a[i] = a[j];
            a[j] = temp;
        }
		//-It returns index of first element which is strictly greater than searched value.
		public static int upperBound(long[] array, int length, long value) {
            int low = 0;
            int high = length;
            while (low < high) {
                final int mid = (low + high) / 2;
                if (value >= array[mid]) {
                    low = mid + 1;
                } else {
                    high = mid;
                }
        }
        return low;
    }
	/*If searched element doesn't exist function returns index of first element which is bigger than searched value.<br>
 * -If searched element is bigger than any array element function returns first index after last element.<br>
 * -If searched element is lower than any array element function returns index of first element.<br>
 * -If there are many values equals searched value function returns first occurrence.<br>*/
	public static int lowerBound(long[] array, int length, long value) {
        int low = 0;
        int high = length;
        while (low < high) {
            final int mid = (low + high) / 2;
            if (value <= array[mid]) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }
        return low;
    }
        
 
}