Problem: There is a weighted tree with n nodes and n-1 edges. The nodes are conveniently labeled from 1 to n. The weights are positive integers at most 100. Define the distance between two nodes to be the sum of edges on the unique path between the nodes. You would like to find the diameter of the tree. Diameter is the maximum distance between a pair of nodes.

Unfortunately, the tree isn't given to you, but you can ask some questions about it. In one question, you can specify two nonempty disjoint sets of nodes p and q, and the judge will return the maximum distance between a node in p and a node in q. In the words, maximum distance between x and y, where x ∈ p and y ∈ q. After asking not more than 9 questions, you must report the maximum distance between any pair of nodes.

Interaction

Each test contains multiple test cases. The first line contains the number of test cases t (1 ≤ t ≤ 1 000). Description of the test cases follows.

The first line of each test case contains an integer n (2 ≤ n ≤ 100) — the number of nodes in the tree.

To ask a question, print "k_1\ k_2\ a_1\ a_2\ …\ a_{k_1}\ b_1\ b_2\ …\ b_{k_2}" (k_1, k_2 ≥ 1 and k_1+k_2 ≤ n). These two sets must be nonempty and disjoint. The judge will respond with a single integer max_{p,q} dist(a_p, b_q). If you ever get a result of -1 (because you printed an invalid query), exit immediately to avoid getting other verdicts.

After printing a query do not forget to output end of line and flush the output. Otherwise, you will get Idleness limit exceeded. To do this, use:

  * fflush(stdout) or cout.flush() in C++;
  * System.out.flush() in Java;
  * flush(output) in Pascal;
  * stdout.flush() in Python;
  * see documentation for other languages.



When you are ready to answer, print "-1\ d", where d is the maximum shortest distance over all pairs of nodes.

You can only ask at most 9 questions per test case.

Hack Format

To hack, use the following format. Note that you can only hack with one test case.

The first line should contain a single integer t (t=1).

The second line should contain a single integer n (2 ≤ n ≤ 100).

Each of the next n-1 lines should contain three integers a_i, b_i, c_i (1≤ a_i, b_i≤ n, 1 ≤ c_i ≤ 100). This denotes an undirected edge between nodes a_i and b_i with weight c_i. These edges must form a tree.

Example

Input


2
5
9
6
10
9
10
2
99


Output


1 4 1 2 3 4 5
1 4 2 3 4 5 1
1 4 3 4 5 1 2
1 4 4 5 1 2 3
1 4 5 1 2 3 4
-1 10
1 1 1 2
-1 99

Note

In the first example, the first tree looks as follows: <image>

In the first question, we have p = {1}, and q = {2, 3, 4, 5}. The maximum distance between a node in p and a node in q is 9 (the distance between nodes 1 and 5).

The second tree is a tree with two nodes with an edge with weight 99 between them.

Solution (in JAVA):

Solution:
import java.awt.*;
import java.io.*;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.*;
import java.util.List;

import static java.lang.Math.abs;
import static java.lang.Math.max;
import static java.lang.Math.min;


public class ArchiveSolving implements Runnable{

    // SOLUTION AT THE TOP OF CODE!!!
    // HACK ME PLEASE IF YOU CAN!!!
    // PLEASE!!!
    // PLEASE!!!
    // PLEASE!!!

    @SuppressWarnings("unused")
    private final static Random rnd = new Random();
    private final static String fileName = "";

    private static long BASE = 1000 * 1000 * 1000 + 7, PHI = BASE - 1;
    private static long MODULO = BASE;


    // THERE SOLUTION STARTS!!!
    private void solve() {
        int tests = readInt();
        while (tests --> 0) {
            int n = readInt();

            int left = 2, right = n;
            int best = query(1, left, right);
            while (right > left) {
                int mid = (left + right) >> 1;
                int leftSize = mid - left + 1;
                int rightSize = right - mid;

                if (leftSize <= rightSize) {
                    int dist = query(1, left, mid);
                    if (dist == best) right = mid;
                    else left = mid + 1;
                } else {
                    int dist = query(1, mid + 1, right);
                    if (dist == best) left = mid + 1;
                    else right = mid;
                }
            }

            out.printAll(1, n - 1, left);
            for (int i = 1; i <= n; ++i) {
                if (i != left) out.print(" " + i);
            }
            out.println();
            out.flush();

            int answer = readInt();
            out.printlnAll(-1, answer);
            out.flush();
        }
    }

    int query(int from, int start, int end) {
        int length = end - start + 1;
        out.printAll(1, length, from);
        for (int i = start; i <= end; ++i) out.print(" " + i);
        out.println();
        out.flush();

        return readInt();
    }

    /////////////////////////////////////////////////////////////////////

    private final static boolean MULTIPLE_TESTS = true;
    private final boolean ONLINE_JUDGE = true;//!new File("input.txt").exists();
//    private final boolean ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE") != null;

    private final static int MAX_STACK_SIZE = 128;

    private final static boolean OPTIMIZE_READ_NUMBERS = true;

    /////////////////////////////////////////////////////////////////////

    @SuppressWarnings("unused")
    private static long inverse(long x) {
        return binpow(x, MODULO - 2);
    }

    private static long binpow(long base, long power) {
        if (power == 0) return 1;
        if ((power & 1) == 0) {
            long half = binpow(base, power >> 1);
            return mult(half, half);
        } else {
            long prev = binpow(base, power - 1);
            return mult(prev, base);
        }
    }

    private static long add(long a, long b) { return (a + b) % MODULO; }

    @SuppressWarnings("unused")
    private static long subtract(long a, long b) { return add(a, MODULO - b % MODULO); }

    private static long mult(long a, long b) { return ((a % MODULO) * (b % MODULO)) % MODULO; }

    /////////////////////////////////////////////////////////////////////

    @SuppressWarnings("unused")
    void yesNo(boolean yes) {
        out.println(yes ? "YES" : "NO");
    }

    /////////////////////////////////////////////////////////////////////

    public void run(){
        try{
            timeInit();
            Locale.setDefault(Locale.US);

            init();

            if (ONLINE_JUDGE) {
                solve();
            } else {
                do {
                    try {
                        timeInit();
                        solve();
                        time();

                        out.println();
                        out.flush();
                    } catch (NumberFormatException | EOFException e) {
                        break;
                    }
                } while (MULTIPLE_TESTS);
            }

            out.close();
            time();
        }catch (Exception e){
            e.printStackTrace(System.err);
            System.exit(-1);
        }
    }

    /////////////////////////////////////////////////////////////////////

    private BufferedReader in;
    private OutputWriter out;
    private StringTokenizer tok = new StringTokenizer("");

    public static void main(String[] args){
        new Thread(null, new ArchiveSolving(), "", MAX_STACK_SIZE * (1L << 20)).start();
    }

    /////////////////////////////////////////////////////////////////////

    private void init() throws FileNotFoundException{
        Locale.setDefault(Locale.US);

        if (ONLINE_JUDGE){
            if (fileName.isEmpty()) {
                in = new BufferedReader(new InputStreamReader(System.in));
                out = new OutputWriter(System.out);
            } else {
                in = new BufferedReader(new FileReader(fileName + ".in"));
                out = new OutputWriter(fileName + ".out");
            }
        }else{
            in = new BufferedReader(new FileReader("input.txt"));
            out = new OutputWriter("output.txt");
        }
    }

    ////////////////////////////////////////////////////////////////

    private long timeBegin;

    private void timeInit() {
        this.timeBegin = System.currentTimeMillis();
    }

    private void time(){
        long timeEnd = System.currentTimeMillis();
        System.err.println("Time = " + (timeEnd - timeBegin));
    }

    @SuppressWarnings("unused")
    private void debug(Object... objects){
        if (ONLINE_JUDGE){
            for (Object o: objects){
                System.err.println(o.toString());
            }
        }
    }

    /////////////////////////////////////////////////////////////////////

    private String delim = " ";

    private String readNullableLine() {
        try {
            return in.readLine();
        } catch (IOException e) {
            throw new RuntimeIOException(e);
        }
    }

    private String readLine() {
        String line = readNullableLine();
        if (null == line) throw new EOFException();
        return line;
    }

    private String readString() {
        while(!tok.hasMoreTokens()){
            tok = new StringTokenizer(readLine(), delim);
        }

        return tok.nextToken(delim);
    }

    /////////////////////////////////////////////////////////////////

    private final char NOT_A_SYMBOL = '\0';

    @SuppressWarnings("unused")
    private char readChar() {
        try {
            int intValue = in.read();

            if (intValue == -1){
                return NOT_A_SYMBOL;
            }

            return (char) intValue;
        } catch (IOException e) {
            throw new RuntimeIOException(e);
        }
    }

    private char[] readCharArray() {
        return readLine().toCharArray();
    }

    @SuppressWarnings("unused")
    private char[][] readCharField(int rowsCount) {
        char[][] field = new char[rowsCount][];
        for (int row = 0; row < rowsCount; ++row) {
            field[row] = readCharArray();
        }

        return field;
    }

    /////////////////////////////////////////////////////////////////

    private long optimizedReadLong() {
        int sign = 1;
        long result = 0;
        boolean started = false;
        while (true) {
            try {
                int j = in.read();
                if (-1 == j) {
                    if (started) return sign * result;
                    throw new NumberFormatException();
                }

                if (j == '-') {
                    if (started) throw new NumberFormatException();
                    sign = -sign;
                }

                if ('0' <= j && j <= '9') {
                    result = result * 10 + j - '0';
                    started = true;
                } else if (started) {
                    return sign * result;
                }
            } catch (IOException e) {
                throw new RuntimeIOException(e);
            }
        }
    }

    private int readInt() {

        if (!OPTIMIZE_READ_NUMBERS) {
            return Integer.parseInt(readString());
        } else {
            return (int) optimizedReadLong();
        }
    }

    private int[] readIntArray(int size) {
        int[] array = new int[size];

        for (int index = 0; index < size; ++index){
            array[index] = readInt();
        }

        return array;
    }

    @SuppressWarnings("unused")
    private int[] readSortedIntArray(int size) {
        Integer[] array = new Integer[size];

        for (int index = 0; index < size; ++index) {
            array[index] = readInt();
        }
        Arrays.sort(array);

        int[] sortedArray = new int[size];
        for (int index = 0; index < size; ++index) {
            sortedArray[index] = array[index];
        }

        return sortedArray;
    }

    private int[] readIntArrayWithDecrease(int size) {
        int[] array = readIntArray(size);

        for (int i = 0; i < size; ++i) {
            array[i]--;
        }

        return array;
    }

    ///////////////////////////////////////////////////////////////////

    @SuppressWarnings("unused")
    private int[][] readIntMatrix(int rowsCount, int columnsCount) {
        int[][] matrix = new int[rowsCount][];

        for (int rowIndex = 0; rowIndex < rowsCount; ++rowIndex) {
            matrix[rowIndex] = readIntArray(columnsCount);
        }

        return matrix;
    }

    @SuppressWarnings("unused")
    private int[][] readIntMatrixWithDecrease(int rowsCount, int columnsCount) {
        int[][] matrix = new int[rowsCount][];

        for (int rowIndex = 0; rowIndex < rowsCount; ++rowIndex) {
            matrix[rowIndex] = readIntArrayWithDecrease(columnsCount);
        }

        return matrix;
    }

    ///////////////////////////////////////////////////////////////////

    private long readLong() {
        if (!OPTIMIZE_READ_NUMBERS) {
            return Long.parseLong(readString());
        } else {
            return optimizedReadLong();
        }
    }

    @SuppressWarnings("unused")
    private long[] readLongArray(int size) {
        long[] array = new long[size];

        for (int index = 0; index < size; ++index){
            array[index] = readLong();
        }

        return array;
    }

    ////////////////////////////////////////////////////////////////////

    private double readDouble() {
        return Double.parseDouble(readString());
    }

    @SuppressWarnings("unused")
    private double[] readDoubleArray(int size) {
        double[] array = new double[size];

        for (int index = 0; index < size; ++index){
            array[index] = readDouble();
        }

        return array;
    }

    ////////////////////////////////////////////////////////////////////

    @SuppressWarnings("unused")
    private BigInteger readBigInteger() {
        return new BigInteger(readString());
    }

    @SuppressWarnings("unused")
    private BigDecimal readBigDecimal() {
        return new BigDecimal(readString());
    }

    /////////////////////////////////////////////////////////////////////

    private Point readPoint() {
        int x = readInt();
        int y = readInt();
        return new Point(x, y);
    }

    @SuppressWarnings("unused")
    private Point[] readPointArray(int size) {
        Point[] array = new Point[size];

        for (int index = 0; index < size; ++index){
            array[index] = readPoint();
        }

        return array;
    }

    /////////////////////////////////////////////////////////////////////

    @Deprecated
    @SuppressWarnings("unused")
    private List<Integer>[] readGraph(int vertexNumber, int edgeNumber) {
        @SuppressWarnings("unchecked")
        List<Integer>[] graph = new List[vertexNumber];

        for (int index = 0; index < vertexNumber; ++index){
            graph[index] = new ArrayList<>();
        }

        while (edgeNumber-- > 0){
            int from = readInt() - 1;
            int to = readInt() - 1;

            graph[from].add(to);
            graph[to].add(from);
        }

        return graph;
    }

    private static class GraphBuilder {

        final int size;
        final List<Integer>[] edges;

        static GraphBuilder createInstance(int size) {
            @SuppressWarnings("unchecked")
            List<Integer>[] edges = new List[size];
            for (int v = 0; v < size; ++v) {
                edges[v] = new ArrayList<>();
            }

            return new GraphBuilder(edges);
        }

        private GraphBuilder(List<Integer>[] edges) {
            this.size = edges.length;
            this.edges = edges;
        }

        public void addEdge(int from, int to) {
            addDirectedEdge(from, to);
            addDirectedEdge(to, from);
        }

        public void addDirectedEdge(int from, int to) {
            edges[from].add(to);
        }

        public int[][] build() {
            int[][] graph = new int[size][];
            for (int v = 0; v < size; ++v) {
                List<Integer> vEdges = edges[v];
                graph[v] = castInt(vEdges);
            }

            return graph;
        }
    }

    @SuppressWarnings("unused")
    private final static int ZERO_INDEXATION = 0, ONE_INDEXATION = 1;

    @SuppressWarnings("unused")
    private int[][] readUnweightedGraph(int vertexNumber, int edgesNumber) {
        return readUnweightedGraph(vertexNumber, edgesNumber, ONE_INDEXATION, false);
    }

    private int[][] readUnweightedGraph(int vertexNumber, int edgesNumber,
                                        int indexation, boolean directed
    ) {
        GraphBuilder graphBuilder = GraphBuilder.createInstance(vertexNumber);
        for (int i = 0; i < edgesNumber; ++i) {
            int from = readInt() - indexation;
            int to = readInt() - indexation;

            if (directed) graphBuilder.addDirectedEdge(from, to);
            else graphBuilder.addEdge(from, to);
        }

        return graphBuilder.build();
    }

    private static class Edge {
        int to;
        int w;

        Edge(int to, int w) {
            this.to = to;
            this.w = w;
        }
    }

    @SuppressWarnings("unused")
    private Edge[][] readWeightedGraph(int vertexNumber, int edgesNumber) {
        return readWeightedGraph(vertexNumber, edgesNumber, ONE_INDEXATION, false);
    }

    private Edge[][] readWeightedGraph(int vertexNumber, int edgesNumber,
                                       int indexation, boolean directed) {
        @SuppressWarnings("unchecked")
        List<Edge>[] graph = new List[vertexNumber];
        for (int v = 0; v < vertexNumber; ++v) {
            graph[v] = new ArrayList<>();
        }

        while (edgesNumber --> 0) {
            int from = readInt() - indexation;
            int to = readInt() - indexation;
            int w = readInt();

            graph[from].add(new Edge(to, w));
            if (!directed) graph[to].add(new Edge(from, w));
        }

        Edge[][] graphArrays = new Edge[vertexNumber][];
        for (int v = 0; v < vertexNumber; ++v) {
            graphArrays[v] = graph[v].toArray(new Edge[0]);
        }

        return graphArrays;
    }

    /////////////////////////////////////////////////////////////////////

    private static class IntIndexPair {

        @SuppressWarnings("unused")
        static Comparator<IntIndexPair> increaseComparator = new Comparator<ArchiveSolving.IntIndexPair>() {
            @Override
            public int compare(ArchiveSolving.IntIndexPair indexPair1, ArchiveSolving.IntIndexPair indexPair2) {
                int value1 = indexPair1.value;
                int value2 = indexPair2.value;

                if (value1 != value2) return value1 - value2;

                int index1 = indexPair1.index;
                int index2 = indexPair2.index;

                return index1 - index2;
            }
        };

        @SuppressWarnings("unused")
        static Comparator<IntIndexPair> decreaseComparator = new Comparator<ArchiveSolving.IntIndexPair>() {
            @Override
            public int compare(ArchiveSolving.IntIndexPair indexPair1, ArchiveSolving.IntIndexPair indexPair2) {
                int value1 = indexPair1.value;
                int value2 = indexPair2.value;

                if (value1 != value2) return -(value1 - value2);

                int index1 = indexPair1.index;
                int index2 = indexPair2.index;

                return index1 - index2;
            }
        };

        @SuppressWarnings("unused")
        static IntIndexPair[] from(int[] array) {
            IntIndexPair[] iip = new IntIndexPair[array.length];
            for (int i = 0; i < array.length; ++i) {
                iip[i] = new IntIndexPair(array[i], i);
            }

            return iip;
        }

        int value, index;

        IntIndexPair(int value, int index) {
            super();
            this.value = value;
            this.index = index;
        }

        @SuppressWarnings("unused")
        int getRealIndex() {
            return index + 1;
        }
    }

    @SuppressWarnings("unused")
    private IntIndexPair[] readIntIndexArray(int size) {
        IntIndexPair[] array = new IntIndexPair[size];

        for (int index = 0; index < size; ++index) {
            array[index] = new IntIndexPair(readInt(), index);
        }

        return array;
    }

    /////////////////////////////////////////////////////////////////////

    private static class OutputWriter extends PrintWriter {

        final int DEFAULT_PRECISION = 12;

        private int precision;
        private String format, formatWithSpace;

        {
            precision = DEFAULT_PRECISION;

            format = createFormat(precision);
            formatWithSpace = format + " ";
        }

        OutputWriter(OutputStream out) {
            super(out);
        }

        OutputWriter(String fileName) throws FileNotFoundException {
            super(fileName);
        }

        int getPrecision() {
            return precision;
        }

        void setPrecision(int precision) {
            precision = max(0, precision);
            this.precision = precision;

            format = createFormat(precision);
            formatWithSpace = format + " ";
        }

        String createFormat(int precision){
            return "%." + precision + "f";
        }

        @Override
        public void print(double d){
            printf(format, d);
        }

        @Override
        public void println(double d){
            print(d);
            println();
        }

        void printWithSpace(double d){
            printf(formatWithSpace, d);
        }

        void printAll(double...d){
            for (int i = 0; i < d.length - 1; ++i){
                printWithSpace(d[i]);
            }

            print(d[d.length - 1]);
        }

        @SuppressWarnings("unused")
        void printlnAll(double... d){
            printAll(d);
            println();
        }

        void printAll(int... array) {
            for (int value : array) {
                print(value + " ");
            }
        }

        @SuppressWarnings("unused")
        void printlnAll(int... array) {
            printAll(array);
            println();
        }

        void printIndexes(int... indexes) {
            for (int index : indexes) {
                print((index + 1) + " ");
            }
        }

        @SuppressWarnings("unused")
        void printlnIndexes(int... indexes) {
            printIndexes(indexes);
            println();
        }

        void printAll(long... array) {
            for (long value : array) {
                print(value + " ");
            }
        }

        @SuppressWarnings("unused")
        void printlnAll(long... array) {
            printAll(array);
            println();
        }
    }

    /////////////////////////////////////////////////////////////////////

    private static class EOFException extends RuntimeException {

        EOFException() {
            super();
        }
    }

    private static class RuntimeIOException extends RuntimeException {

        /**
         *
         */
        private static final long serialVersionUID = -6463830523020118289L;

        RuntimeIOException(Throwable cause) {
            super(cause);
        }
    }

    /////////////////////////////////////////////////////////////////////
    //////////////// Some useful constants andTo functions ////////////////
    /////////////////////////////////////////////////////////////////////

    private static void swap(int[] array, int i, int j) {
        if (i != j) {
            int tmp = array[i];
            array[i] = array[j];
            array[j] = tmp;
        }
    }

    private static <T> void swap(T[] array, int i, int j) {
        if (i != j) {
            T tmp = array[i];
            array[i] = array[j];
            array[j] = tmp;
        }
    }

    private static final int[][] steps = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}};
    private static final int[][] steps8 = {
            {-1, 0}, {1, 0}, {0, -1}, {0, 1},
            {-1, -1}, {1, 1}, {1, -1}, {-1, 1}
    };

    @SuppressWarnings("unused")
    private static boolean checkCell(int row, int rowsCount, int column, int columnsCount) {
        return checkIndex(row, rowsCount) && checkIndex(column, columnsCount);
    }

    private static boolean checkIndex(int index, int lim){
        return (0 <= index && index < lim);
    }

    /////////////////////////////////////////////////////////////////////

    private static int getBit(long mask, int bit) { return (int)((mask >> bit) & 1); }

    @SuppressWarnings("unused")
    private static boolean checkBit(long mask, int bit){
        return getBit(mask, bit) != 0;
    }

    /////////////////////////////////////////////////////////////////////

    @SuppressWarnings("unused")
    private static long getSum(int[] array) {
        long sum = 0;
        for (int value: array) {
            sum += value;
        }

        return sum;
    }

    @SuppressWarnings("unused")
    private static Point getMinMax(int[] array) {
        int min = array[0];
        int max = array[0];

        for (int index = 0, size = array.length; index < size; ++index, ++index) {
            int value = array[index];

            if (index == size - 1) {
                min = min(min, value);
                max = max(max, value);
            } else {
                int otherValue = array[index + 1];

                if (value <= otherValue) {
                    min = min(min, value);
                    max = max(max, otherValue);
                } else {
                    min = min(min, otherValue);
                    max = max(max, value);
                }
            }
        }

        return new Point(min, max);
    }

    /////////////////////////////////////////////////////////////////////

    @SuppressWarnings("unused")
    private static boolean isPrime(int x) {
        if (x < 2) return false;
        for (int d = 2; d * d <= x; ++d) {
            if (x % d == 0) return false;
        }

        return true;
    }

    @SuppressWarnings("unused")
    private static int[] getPrimes(int n) {
        boolean[] used = new boolean[n];
        used[0] = used[1] = true;

        int size = 0;
        for (int i = 2; i < n; ++i) {
            if (!used[i]) {
                ++size;
                for (int j = 2 * i; j < n; j += i) {
                    used[j] = true;
                }
            }
        }

        int[] primes = new int[size];
        for (int i = 0, cur = 0; i < n; ++i) {
            if (!used[i]) {
                primes[cur++] = i;
            }
        }

        return primes;
    }

    /////////////////////////////////////////////////////////////////////

    @SuppressWarnings("unused")
    static int[] getDivisors(int value) {
        List<Integer> divisors = new ArrayList<>();
        for (int divisor = 1; divisor * divisor <= value; ++divisor) {
            if (value % divisor == 0) {
                divisors.add(divisor);
                if (divisor * divisor != value) {
                    divisors.add(value / divisor);
                }
            }
        }

        return castInt(divisors);
    }

    @SuppressWarnings("unused")
    static long[] getDivisors(long value) {
        List<Long> divisors = new ArrayList<>();
        for (long divisor = 1; divisor * divisor <= value; ++divisor) {
            if (value % divisor == 0) {
                divisors.add(divisor);
                if (divisor * divisor != value) {
                    divisors.add(value / divisor);
                }
            }
        }

        return castLong(divisors);
    }

    /////////////////////////////////////////////////////////////////////

    @SuppressWarnings("unused")
    private static long lcm(long a, long b) {
        return a / gcd(a, b) * b;
    }

    private static long gcd(long a, long b) {
        return (a == 0 ? b : gcd(b % a, a));
    }

    /////////////////////////////////////////////////////////////////////

    private static int[] castInt(List<Integer> list) {
        int[] array = new int[list.size()];
        for (int i = 0; i < array.length; ++i) {
            array[i] = list.get(i);
        }

        return array;
    }

    @SuppressWarnings("unused")
    private static long[] castLong(List<Long> list) {
        long[] array = new long[list.size()];
        for (int i = 0; i < array.length; ++i) {
            array[i] = list.get(i);
        }

        return array;
    }

    /////////////////////////////////////////////////////////////////////

    /**
     * Generates list with keys 0..<n
     * @param n - exclusive limit of sequence
     */
    @SuppressWarnings("unused")
    private static List<Integer> order(int n) {
        List<Integer> sequence = new ArrayList<>();
        for (int i = 0; i < n; ++i) {
            sequence.add(i);
        }

        return sequence;
    }

    @SuppressWarnings("unused")
    private static List<Integer> shuffled(List<Integer> list) {
        Collections.shuffle(list, rnd);
        return list;
    }
}