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:
// package cf.cf1348;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.*;
import java.util.function.IntConsumer;

public class CFB {
    private static final String INPUT = "4\n" +
            "4 2\n" +
            "1 2 2 1\n" +
            "4 3\n" +
            "1 2 2 1\n" +
            "3 2\n" +
            "1 2 3\n" +
            "4 4\n" +
            "4 3 4 2\n";
    private static final int MOD = 1_000_000_007;

    FastScanner sc;
    PrintWriter out;

    public static void main(String[] args) {
        new CFB().run();
    }

    public CFB() {
        sc = new FastScanner(oj ? System.in : new ByteArrayInputStream(INPUT.getBytes()));
        out = new PrintWriter(System.out);
    }

    public void run() {
        long start = System.currentTimeMillis();
        times(sc.nextInt(), this::solve);
        out.flush();
        tr(System.currentTimeMillis() - start + "ms");
    }

    public void solve(int time) {
        int n = sc.nextInt();
        int k = sc.nextInt();
        int[] a = readIntArray(n);

        Map<Integer, Integer> map = new HashMap<>(n / 2);
        for (int i : a) map.compute(i, (key, val) -> val == null ? 1 : val + 1);

        if (map.size() > k) answer(-1);

        writeln(k * n);
        int[] set = map.keySet().stream().mapToInt(i -> i).toArray();
        for (int i = 0; i < n; i++) {
            for (int j = 0, iset = 0; j < k; j++, iset++) {
                write(set[iset % set.length] + " ");
            }
        }
        writeln();
    }

    //---------------------------------------------------------------------------------------------------

    /**
     * If searched element doesn't exist, 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>
     */
    private static int lowerBound(long[] arr, long key) {
        int lo = 0;
        int hi = arr.length - 1;
        while (lo < hi) {
            int mid = (lo + hi) / 2;
            if (key <= arr[mid]) {
                hi = mid - 1;
            } else {
                lo = mid + 1;
            }
        }
        return arr[lo] < key ? lo + 1 : lo;
    }

    /**
     * Returns index of first element which is grater than searched value.
     * If searched element is bigger than any array element, returns first index after last element.
     */
    private static int upperBound(long[] arr, long key) {
        int lo = 0;
        int hi = arr.length - 1;
        while (lo < hi) {
            int mid = (lo + hi) / 2;
            if (key >= arr[mid]) {
                lo = mid + 1;
            } else {
                hi = mid;
            }
        }
        return arr[lo] <= key ? lo + 1 : lo;
    }

    private long[] prefixSum(long[] array) {
        long[] result = new long[array.length];
        result[0] = array[0];
        for (int i = 1; i < array.length; i++) result[i] = result[i - 1] + array[i];
        return result;
    }

    private int[] sort(int[] array) {
        shuffle(array);
        Arrays.sort(array);
        return array;
    }

    private static void shuffle(int[] array) {
        Random random = new Random();
        for (int i = array.length - 1; i > 0; i--) {
            int index = random.nextInt(i + 1);
            {
                int tmp = array[index];
                array[index] = array[i];
                array[i] = tmp;
            }
        }
    }

    private long[] sort(long[] array) {
        shuffle(array);
        Arrays.sort(array);
        return array;
    }

    private static void shuffle(long[] array) {
        Random random = new Random();
        for (int i = array.length - 1; i > 0; i--) {
            int index = random.nextInt(i + 1);
            {
                long tmp = array[index];
                array[index] = array[i];
                array[i] = tmp;
            }
        }
    }

    static class ExitException extends RuntimeException {
    }

    private int iread() {
        int res = sc.nextInt();
        if (res <= 0) {
            throw new ExitException();
        }
        return res;
    }

    private void iwrite(char[] chars) {
        for (char chr : chars) {
            out.print(chr);
        }
        out.println();
        out.flush();
    }

    private void write(Object obj) {
        out.print(obj);
    }

    private void writeln(Object obj) {
        out.println(obj);
    }

    private void writeln() {
        out.println();
    }

    private void answer(Object ans) {
        out.println(ans);
        throw new ExitException();
    }

    private void times(int n, IntConsumer consumer) {
        for (int i = 0; i < n; i++) {
            try {
                consumer.accept(i);
            } catch (ExitException ignored) {
            }
        }
    }

    private int[] readIntArray(int n) {
        int[] res = new int[n];
        for (int i = 0; i < n; i++) {
            res[i] = sc.nextInt();
        }
        return res;
    }

    private long[] readLongArray(int n) {
        long[] res = new long[n];
        for (int i = 0; i < n; i++) {
            res[i] = sc.nextLong();
        }
        return res;
    }

    static class FastScanner {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;

        FastScanner(InputStream stream) {
            this.stream = stream;
        }

        int read() {
            if (numChars == -1)
                throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) return -1;
            }
            return buf[curChar++];
        }

        boolean isSpaceChar(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        boolean isEndline(int c) {
            return c == '\n' || c == '\r' || c == -1;
        }

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

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

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

        public String next() {
            int c = read();
            while (isSpaceChar(c)) c = read();
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public String nextLine() {
            int c = read();
            while (isEndline(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isEndline(c));
            return res.toString();
        }

    }

    private boolean oj = System.getProperty("ONLINE_JUDGE") != null;

    private void tr(Object... o) {
        if (!oj) System.out.println(Arrays.deepToString(o));
    }
}