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:
// Working program with FastReader 
import java.io.*;
import java.util.*;
public class ll
{ 
    static 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; 
        } 
    } 

    static final int MAXN = 100001;
    // stores smallest prime factor for every number
    static int spf[] = new int[MAXN];
    // Calculating SPF (Smallest Prime Factor) for every
    // number till MAXN.
    // Time Complexity : O(nloglogn)
    static void sieve()
    {
        spf[1] = 1;
        for (int i=2; i<MAXN; i++)

        // marking smallest prime factor for every
        // number to be itself.
            spf[i] = i;

        // separately marking spf for every even
        // number as 2
        for (int i=4; i<MAXN; i+=2)
            spf[i] = 2;

        for (int i=3; i*i<MAXN; i++)
        {
            // checking if i is prime
            if (spf[i] == i)
            {
                // marking SPF for all numbers divisible by i
                for (int j=i*i; j<MAXN; j+=i)

                // marking spf[j] if it is not
                // previously marked
                    if (spf[j]==j)
                        spf[j] = i;
            }
        }
    }
    // A O(log n) function returning primefactorization
    // by dividing by smallest prime factor at every step
    static int getFactorization(int x)
    {
        int c=0;
        while (x != 1)
        {
            c++;
            x = x / spf[x];
        }
        return c;
    }

    /*
    static int LowerBound(int a[], int x) { // x is the target value or key
    int l=-1,r=a.length;
    while(l+1<r) {
    int m=(l+r)>>>1;
    if(a[m]>=x) r=m;
    else l=m;
    }
    return r;
    }

    static int UpperBound(int a[], int x) {// x is the key or target value
    int l=-1,r=a.length;
    while(l+1<r) {
    int m=(l+r)>>>1;
    if(a[m]<=x) l=m;
    else r=m;
    }
    return l+1;
    }
     */
    static int gcd(int a, int b)
    {
        if (a == 0)
            return b; 
        return gcd(b % a, a); 
    }

    // method to return LCM of two numbers
    static int lcm(int a, int b)
    {
        return (a / gcd(a, b)) * b;
    }

    public static int[] swap(int a[], int left, int right)
    {
        int temp = a[left];
        a[left] = a[right];
        a[right] = temp;
        return a;
    }

    public static int[] reverse(int a[], int left, int right)
    {
        // Reverse the sub-array
        while (left < right) {
            int temp = a[left];
            a[left++] = a[right];
            a[right--] = temp;
        }
        return a;
    }

    public static int[] findNextPermutation(int a[])
    {
        int last = a.length - 2;

        // find the longest non-increasing suffix
        // and find the pivot
        while (last >= 0) {
            if (a[last] < a[last + 1]) {
                break;
            }
            last--;
        }
        // If there is no increasing pair
        // there is no higher order permutation
        if (last < 0)
            return a;

        int nextGreater = a.length - 1;

        // Find the rightmost successor to the pivot
        for (int i = a.length - 1; i > last; i--) {
            if (a[i] > a[last]) {
                nextGreater = i;
                break;
            }
        }

        // Swap the successor and the pivot
        a = swap(a, nextGreater, last);

        // Reverse the suffix
        a = reverse(a, last + 1, a.length - 1);

        // Return true as the next_permutation is done
        return a;
    }

    static void sort(int[] a) {
        ArrayList<Integer> l = new ArrayList<>();
        for (int i : a)
            l.add(i);
        Collections.sort(l);
        for (int i = 0; i < a.length; i++)
            a[i] = l.get(i);
    }
    static void sort(char[] a) {
        ArrayList<Character> l = new ArrayList<>();
        for (char i : a)
            l.add(i);
        Collections.sort(l);
        for (char i = 0; i < a.length; i++)
            a[i] = l.get(i);
    }

    static double pow(double p,double tt)
    {
        double ii,q,r;
        q=1;
        r=p;
        while(tt>1)
        {
            for(ii=1;2*ii<=tt;ii*=2)
                p*=p;
            tt-=ii;
            q*=p;
            p=r;
        }
        if(tt==1)
            q*=r;
        return q;
    }

    static long pow(long p,long tt,long mod)
    {
        long ii,q,r;
        q=1l;
        r=p;
        while(tt>1)
        {
            for(ii=1l;2*ii<=tt;ii*=2l)
                p=((p%mod)*(p%mod))%mod;
            tt-=ii;
            q=((q%mod)*(p%mod))%mod;
            p=r;
        }
        if(tt==1)
            q=((q%mod)*(r%mod))%mod;
        return q;
    }

    static int factorial(int n)
    {
        return (n == 1 || n == 0) ? 1 : n * factorial(n - 1);
    }

    public static long primeFactors(long n)
    {
        long c=0l;
        long max=0l;
        long z=0l;
        //ArrayList <Integer> ll=new ArrayList<>();
        // Print the number of 2s that divide n
        while (n%2==0)
        {
            c++;
            n /= 2l;
            //ll.add(2);
        }
        if(c>max)
        {
            max=c;
            z=2;
        }
        // n must be odd at this point. So we can
        // skip one element (Note i = i +2)
        for (int i = 3; i <= Math.sqrt(n); i+= 2)
        {
            // While i divides n, print i and divide n
            c=0;
            while (n%i == 0)
            {
                c++;
                n /= i;
                //ll.add(i);
            }
            if(c>max)
            {
                max=c;
                z=i;
            }
        }
        c=0;
        // This condition is to handle the case whien
        // n is a prime number greater than 2
        if (n > 2)
        {
            c++;
            //ll.add((int)n);
        }
        if(c>max)
        {
            max=c;
            z=n;
        }
        return z;
    }

    static void PrimeList(){
        int i,j;
        int sieve[]=new int[100001];
        for(i=2;i*i<=100000;i++)
        {
            if(sieve[i]==0)
            {
                for(j=i*i;j<=100000;j+=i)
                    sieve[j]=1;
            }
        }
        ArrayList<Integer> primes=new ArrayList<>();
        for(i=2;i<=100000;i++)
        {
            if(sieve[i]==0)
                primes.add(i);
        }
    }

    static int comp(int a[],int b[],int n)
    {
        int z=0;
        for(int i=0;i<n;i++)
        {
            if(a[i]!=b[i])
            {
                z=1;
                break;
            }
        }
        if(z==0)
            return 1;
        else
            return 0;
    }

    static boolean isPowerOfTwo(int x)
    {
        return x!=0 && ((x&(x-1))==0);
    }
    public static void main(String[] args) 
    {
        //try
        //{
        FastReader d=new FastReader();
        PrintWriter pr = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
        int t,i,j,k,l,r,n;
        int mod = (int) 1e9 + 7;

        int Inf=Integer.MAX_VALUE;
        int negInf=Integer.MIN_VALUE;
        t=d.nextInt();
        //t=1;
        //String s;
        //char ch1,ch2,ch3,ch4;
        long ans,c,z;

        while(t-->0)
        {
            z=c=0l;
            ans=0l;
            n=d.nextInt();
            k=d.nextInt();
            Set <Integer>s=new HashSet<>();
            int a[]=new int[n];
            for(i=0;i<n;i++)
            {
                a[i]=d.nextInt();
                s.add(a[i]);
            }
            if(s.size()>k)
            pr.println(-1);
            else
            {
                ArrayList<Integer>aa=new ArrayList<>();
                ArrayList<Integer>bb=new ArrayList<>();
                l=0;
                for(i=0;i<n;i++)
                {
                    if(s.contains(a[i]))
                    {
                        aa.add(a[i]);
                        l++;
                        s.remove(a[i]);
                    }
                }
                while(l<k)
                {
                    aa.add(a[0]);
                    l++;
                }
                for(i=0;i<n;i++)
                {
                    for(j=0;j<k;j++)
                    bb.add(aa.get(j));
                }
                pr.println(bb.size());
                for(i=0;i<bb.size();i++)
                pr.print(bb.get(i)+" ");
                pr.println();
            }
        }
        /*
        }catch(Exception e) {
        System.out.println(0);
        }*/  
        pr.flush();
    }
}