Problem: You are given an undirected unweighted connected graph consisting of n vertices and m edges. It is guaranteed that there are no self-loops or multiple edges in the given graph.

Your task is to choose at most ⌊n/2⌋ vertices in this graph so each unchosen vertex is adjacent (in other words, connected by an edge) to at least one of chosen vertices.

It is guaranteed that the answer exists. If there are multiple answers, you can print any.

You will be given multiple independent queries to answer.

Input

The first line contains a single integer t (1 ≤ t ≤ 2 ⋅ 10^5) — the number of queries.

Then t queries follow.

The first line of each query contains two integers n and m (2 ≤ n ≤ 2 ⋅ 10^5, n - 1 ≤ m ≤ min(2 ⋅ 10^5, (n(n-1))/(2))) — the number of vertices and the number of edges, respectively.

The following m lines denote edges: edge i is represented by a pair of integers v_i, u_i (1 ≤ v_i, u_i ≤ n, u_i ≠ v_i), which are the indices of vertices connected by the edge.

There are no self-loops or multiple edges in the given graph, i. e. for each pair (v_i, u_i) there are no other pairs (v_i, u_i) or (u_i, v_i) in the list of edges, and for each pair (v_i, u_i) the condition v_i ≠ u_i is satisfied. It is guaranteed that the given graph is connected.

It is guaranteed that ∑ m ≤ 2 ⋅ 10^5 over all queries.

Output

For each query print two lines.

In the first line print k (1 ≤ ⌊n/2⌋) — the number of chosen vertices.

In the second line print k distinct integers c_1, c_2, ..., c_k in any order, where c_i is the index of the i-th chosen vertex.

It is guaranteed that the answer exists. If there are multiple answers, you can print any.

Example

Input


2
4 6
1 2
1 3
1 4
2 3
2 4
3 4
6 8
2 5
5 4
4 3
4 1
1 3
2 3
2 6
5 6


Output


2
1 3
3
4 3 6

Note

In the first query any vertex or any pair of vertices will suffice.

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Note that you don't have to minimize the number of chosen vertices. In the second query two vertices can be enough (vertices 2 and 4) but three is also ok.

<image>

Solution (in JAVA):

Solution:
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.io.OutputStreamWriter;
import java.util.NoSuchElementException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Iterator;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.Writer;
import java.util.Comparator;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author cplayer
 */
public class Main {
    public static void main (String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        ECoverIt solver = new ECoverIt();
        int testCount = Integer.parseInt(in.next());
        for (int i = 1; i <= testCount; i++)
            solver.solve(i, in, out);
        out.close();
    }

    static class ECoverIt {
        private IntList[] graph;
        private int[] used;
        private IntList res;

        public void solve (int testNumber, InputReader in, OutputWriter out) {
            int n = in.readInt(), m = in.readInt();
            graph = new IntList[n + 1];
            used = new int[n + 1];
            for (int i = 1; i <= n; ++i) {
                graph[i] = new IntArrayList();
            }
            for (int i = 0; i < m; ++i) {
                int from = in.readInt(), to = in.readInt();
                graph[from].add(to);
                graph[to].add(from);
            }
            IntIntPair[] degrees = new IntIntPair[n + 1];
            for (int i = 0; i <= n; ++i) {
                degrees[i] = new IntIntPair(i == 0 ? 0 : graph[i].size(), i);
            }
            Arrays.sort(degrees, Comparator.reverseOrder());
            res = new IntArrayList();
            for (int i = 0; i < degrees.length; ++i) {
                if (degrees[i].second != 0) {
                    mark(degrees[i].second);
                }
                for (int j = 0; j < degrees.length; ++j) {
                    if (degrees[j].second != 0) {
                        if (used[degrees[j].second] == 0) {
                            mark(degrees[j].second);
                        }
                    }
                }
                if (res.size() <= n / 2) {
                    break;
                } else {
                    res = new IntArrayList();
                    Arrays.fill(used, 0);
                }
            }

            out.println(res.size());
            for (int i = 0; i < res.size(); ++i) {
                out.print(res.get(i));
                out.print(i == res.size() - 1 ? '\n' : ' ');
            }
        }

        private void mark (int curIdx) {
            used[curIdx] = 1;
            res.add(curIdx);
            for (int i = 0; i < graph[curIdx].size(); ++i) {
                int nextIdx = graph[curIdx].get(i);
                if (used[nextIdx] == 0) {
                    used[nextIdx] = 1;
                }
            }
        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter (OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter (Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void print (char i) {
            writer.print(i);
        }

        public void close () {
            writer.close();
        }

        public void print (int i) {
            writer.print(i);
        }

        public void println (int i) {
            writer.println(i);
        }

    }

    static class IntArrayList extends IntAbstractStream implements IntList {
        private int size;
        private int[] data;

        public IntArrayList () {
            this(3);
        }

        public IntArrayList (int capacity) {
            data = new int[capacity];
        }

        public IntArrayList (IntCollection c) {
            this(c.size());
            addAll(c);
        }

        public IntArrayList (IntStream c) {
            this();
            if (c instanceof IntCollection) {
                ensureCapacity(((IntCollection) c).size());
            }
            addAll(c);
        }

        public IntArrayList (IntArrayList c) {
            size = c.size();
            data = c.data.clone();
        }

        public IntArrayList (int[] arr) {
            size = arr.length;
            data = arr.clone();
        }

        public int size () {
            return size;
        }

        public int get (int at) {
            if (at >= size) {
                throw new IndexOutOfBoundsException("at = " + at + ", size = " + size);
            }
            return data[at];
        }

        private void ensureCapacity (int capacity) {
            if (data.length >= capacity) {
                return;
            }
            capacity = Math.max(2 * data.length, capacity);
            data = Arrays.copyOf(data, capacity);
        }

        public void addAt (int index, int value) {
            ensureCapacity(size + 1);
            if (index > size || index < 0) {
                throw new IndexOutOfBoundsException("at = " + index + ", size = " + size);
            }
            if (index != size) {
                System.arraycopy(data, index, data, index + 1, size - index);
            }
            data[index] = value;
            size++;
        }

        public void removeAt (int index) {
            if (index >= size || index < 0) {
                throw new IndexOutOfBoundsException("at = " + index + ", size = " + size);
            }
            if (index != size - 1) {
                System.arraycopy(data, index + 1, data, index, size - index - 1);
            }
            size--;
        }

    }

    static class IntIntPair implements Comparable<IntIntPair> {
        public int first;
        public int second;

        public IntIntPair (int first, int second) {
            this.first = first;
            this.second = second;
        }

        public boolean equals (Object o) {
            if (this == o) {
                return true;
            }
            if (o == null || getClass() != o.getClass()) {
                return false;
            }

            IntIntPair pair = (IntIntPair) o;

            return first == pair.first && second == pair.second;
        }

        public int hashCode () {
            int result = first;
            result = 31 * result + second;
            return result;
        }

        public String toString () {
            return "(" + first + "," + second + ")";
        }

        public int compareTo (IntIntPair o) {
            int value = Integer.compare(first, o.first);
            if (value != 0) {
                return value;
            }
            return Integer.compare(second, o.second);
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader (InputStream stream) {
            this.stream = stream;
        }

        public 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++];
        }

        public int readInt () {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

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

        public boolean isSpaceChar (int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

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

        public String next () {
            return readString();
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar (int ch);

        }

    }

    static interface IntList extends IntReversableCollection {
        public abstract int get (int index);

        public abstract void addAt (int index, int value);

        public abstract void removeAt (int index);

        default public IntIterator intIterator () {
            return new IntIterator() {
                private int at;
                private boolean removed;

                public int value () {
                    if (removed) {
                        throw new IllegalStateException();
                    }
                    return get(at);
                }

                public boolean advance () {
                    at++;
                    removed = false;
                    return isValid();
                }

                public boolean isValid () {
                    return !removed && at < size();
                }

                public void remove () {
                    removeAt(at);
                    at--;
                    removed = true;
                }
            };
        }

        default public void add (int value) {
            addAt(size(), value);
        }

    }

    static interface IntReversableCollection extends IntCollection {
    }

    static interface IntStream extends Iterable<Integer>, Comparable<IntStream> {
        public IntIterator intIterator ();

        default public Iterator<Integer> iterator () {
            return new Iterator<Integer>() {
                private IntIterator it = intIterator();

                public boolean hasNext () {
                    return it.isValid();
                }

                public Integer next () {
                    int result = it.value();
                    it.advance();
                    return result;
                }
            };
        }

        default public int compareTo (IntStream c) {
            IntIterator it = intIterator();
            IntIterator jt = c.intIterator();
            while (it.isValid() && jt.isValid()) {
                int i = it.value();
                int j = jt.value();
                if (i < j) {
                    return -1;
                } else if (i > j) {
                    return 1;
                }
                it.advance();
                jt.advance();
            }
            if (it.isValid()) {
                return 1;
            }
            if (jt.isValid()) {
                return -1;
            }
            return 0;
        }

    }

    static abstract class IntAbstractStream implements IntStream {
        public String toString () {
            StringBuilder builder = new StringBuilder();
            boolean first = true;
            for (IntIterator it = intIterator(); it.isValid(); it.advance()) {
                if (first) {
                    first = false;
                } else {
                    builder.append(' ');
                }
                builder.append(it.value());
            }
            return builder.toString();
        }

        public boolean equals (Object o) {
            if (!(o instanceof IntStream)) {
                return false;
            }
            IntStream c = (IntStream) o;
            IntIterator it = intIterator();
            IntIterator jt = c.intIterator();
            while (it.isValid() && jt.isValid()) {
                if (it.value() != jt.value()) {
                    return false;
                }
                it.advance();
                jt.advance();
            }
            return !it.isValid() && !jt.isValid();
        }

        public int hashCode () {
            int result = 0;
            for (IntIterator it = intIterator(); it.isValid(); it.advance()) {
                result *= 31;
                result += it.value();
            }
            return result;
        }

    }

    static interface IntIterator {
        public int value () throws NoSuchElementException;

        public boolean advance ();

        public boolean isValid ();

    }

    static interface IntCollection extends IntStream {
        public int size ();

        default public void add (int value) {
            throw new UnsupportedOperationException();
        }

        default public IntCollection addAll (IntStream values) {
            for (IntIterator it = values.intIterator(); it.isValid(); it.advance()) {
                add(it.value());
            }
            return this;
        }

    }
}