Problem: Phoenix loves beautiful arrays. An array is beautiful if all its subarrays of length k have the same sum. A subarray of an array is any sequence of consecutive elements.

Phoenix currently has an array a of length n. He wants to insert some number of integers, possibly zero, into his array such that it becomes beautiful. The inserted integers must be between 1 and n inclusive. Integers may be inserted anywhere (even before the first or after the last element), and he is not trying to minimize the number of inserted integers.

Input

The input consists of multiple test cases. The first line contains an integer t (1 ≤ t ≤ 50) — the number of test cases.

The first line of each test case contains two integers n and k (1 ≤ k ≤ n ≤ 100).

The second line of each test case contains n space-separated integers (1 ≤ a_i ≤ n) — the array that Phoenix currently has. This array may or may not be already beautiful.

Output

For each test case, if it is impossible to create a beautiful array, print -1. Otherwise, print two lines.

The first line should contain the length of the beautiful array m (n ≤ m ≤ 10^4). You don't need to minimize m.

The second line should contain m space-separated integers (1 ≤ b_i ≤ n) — a beautiful array that Phoenix can obtain after inserting some, possibly zero, integers into his array a. You may print integers that weren't originally in array a.

If there are multiple solutions, print any. It's guaranteed that if we can make array a beautiful, we can always make it with resulting length no more than 10^4.

Example

Input


4
4 2
1 2 2 1
4 3
1 2 2 1
3 2
1 2 3
4 4
4 3 4 2


Output


5
1 2 1 2 1
4
1 2 2 1
-1
7
4 3 2 1 4 3 2

Note

In the first test case, we can make array a beautiful by inserting the integer 1 at index 3 (in between the two existing 2s). Now, all subarrays of length k=2 have the same sum 3. There exists many other possible solutions, for example: 

  * 2, 1, 2, 1, 2, 1 
  * 1, 2, 1, 2, 1, 2 



In the second test case, the array is already beautiful: all subarrays of length k=3 have the same sum 5.

In the third test case, it can be shown that we cannot insert numbers to make array a beautiful.

In the fourth test case, the array b shown is beautiful and all subarrays of length k=4 have the same sum 10. There exist other solutions also.

Solution (in JAVA):

Solution:
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.*;
import java.io.*;
public class Main {
InputStream is;
	PrintWriter out;
	String INPUT = ""; 
//class  Declaration

static class pair implements Comparable<pair>{
	int x;
	int y;
	
	
	pair (int i,int j)
	{ x=i; y=j;
		
	}
	public int compareTo(pair p){
		if(this.x!=p.x) { return this.x-p.x;}
		else { return this.y-p.y;}
	}
	public int hashCode() { return (x+" "+y).hashCode();}
	public String toString(){ return x+" "+y;} 
	public boolean equals(Object o){ 
		pair x = (pair) o ;
		return (x.x==this.x&&x.y==this.y);}
}

long mod  = (long)1e9 + 7 ;
HashMap<String,Long> hm  = new HashMap<>();
long[] wts,val ;
void solve() throws Exception{
	int t=ni();
	while(t-->0){
		int n=ni(),k=ni();
		StringBuilder sb = new StringBuilder();
		int[] arr =new int[n];
		HashSet<Integer> hs = new HashSet<>();
		for(int i=0;i<n;++i){
			arr[i]=ni();
			hs.add(arr[i]);
		}
		if(hs.size()>k){
			pn(-1);
		}
		else{
			for(int x: hs) sb.append(x+" ");
			for(int i=0;i<k-hs.size();++i){
				sb.append(arr[0]+" ");
			}
			StringBuilder ans = new StringBuilder();
			for(int i=0;i<n;++i){
				ans.append(sb);
			}
			pn(n*k);
			pn(ans);
		}
	}

}

long pow(long a,long b){
	long result = 1;
	while(b>0){
	if(b%2==1) result = (result * a) % mod;
		b/=2;
		a=(a*a)%mod;
	}
	return result;
}

void print(Object o){
System.out.println(o);
System.out.flush();
}

int gcd(int a, int b) 
{ 
if (b == 0) 
return a; 
return gcd(b, a % b);  
}
void run() throws Exception{
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
out = new PrintWriter(System.out);
		
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
}
	
	
public static void main(String[] args) throws Exception { new Main().run(); }
	
//output methods
private void pn(Object o)
{
	out.println(o);
}
private void p(Object o)
{
	out.print(o);
}



//input methods
		private byte[] inbuf = new byte[1024];
	public int lenbuf = 0, ptrbuf = 0;
	

	private int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}
	
	
	
	
	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private double nd() { return Double.parseDouble(ns()); }
	private char nc() { return (char)skip(); }
	
	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
		
	private char[][] nm(int n, int m)
	{
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}
	
	private int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private int ni()
	{
		int num = 0, b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private void tr(Object... o) { if(INPUT.length() > 0)System.out.println(Arrays.deepToString(o)); }
	void watch(Object ... a) throws Exception{
		int i=1;
		pn("watch starts :");
		for(Object o : a ) {
			//print(o);
			boolean notfound = true;
			if(o.getClass().isArray()){
				
				String type = o.getClass().getName().toString();
				//print("type is "+type);
				switch (type) {
					case "[I":{
						int[] test = (int[])o ;
						pn(i+" "+Arrays.toString(test));
						break;
					}
					case "[[I":{
						int[][] obj = (int[][])o;
						
						pn(i+" "+Arrays.deepToString(obj));
						break;
					}
					case "[J" : {
						
						long[] obj  = (long[])o ;
						pn(i+" "+Arrays.toString(obj));
						break;
					}
					case "[[J": {
						
						long[][] obj = (long[][])o;
						pn(i+" "+Arrays.deepToString(obj));
						break;
					}
					case "[D" :{
						
						double[] obj= (double[])o;
						pn(i+" "+Arrays.toString(obj));
						break;
					}
					case "[[D" :{
						
						double[][] obj = (double[][])o;
						pn(i+" "+Arrays.deepToString(obj));
						break;
					}
					case "[Ljava.lang.String": {
						
						String[] obj = (String[])o ;
						pn(i+" "+Arrays.toString(obj));
						break;
					}
					case "[[Ljava.lang.String": {
						
						String[][] obj = (String[][])o ;
						pn(i+" "+Arrays.deepToString(obj));
						break ; 
					}
					case "[C" :{
						char[] obj = (char[])o ;
						pn(i+" "+Arrays.toString(obj));
						break;
					}
					case "[[C" :{
						
						char[][] obj = (char[][])o;
						pn(i+" "+Arrays.deepToString(obj));
						break;
					}

						
				
					default:{
						pn(i+" type not identified");
						break;
					}
				}
				notfound = false;
				
			}
			if(o.getClass() == ArrayList.class){
				pn(i+" al: "+o);
				notfound = false;
			}
			if(o.getClass() == HashSet.class){
				pn(i+" hs: "+o);
				notfound = false;
			}
			if(o.getClass() == TreeSet.class){
				pn(i+" ts: "+o);
				notfound = false;
			}
			if(o.getClass() == TreeMap.class){
				pn(i+" tm: "+o);
				notfound = false;
			}
			if(o.getClass() == HashMap.class){
				pn(i+" hm: "+o);
				notfound = false;
			}
			if(o.getClass() == LinkedList.class){
				pn(i+" ll: "+o);
				notfound = false;
			}
			if(o.getClass() == PriorityQueue.class){
				pn(i+" pq : "+o);
				notfound = false;
			}
			if(o.getClass() == pair.class){
				pn(i+" pq : "+o);
				notfound = false;
			}
			
			if(notfound){
				pn(i+" unknown: "+o);
			}
			i++;
		}
		pn("watch ends ");
	}

}