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.

<image>

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 com.sun.org.apache.bcel.internal.generic.ARRAYLENGTH;

import javax.print.DocFlavor;
import javax.print.attribute.standard.RequestingUserName;
import java.io.*;
import java.lang.reflect.Array;
import java.net.Inet4Address;
import java.nio.charset.IllegalCharsetNameException;
import java.time.temporal.Temporal;
import java.time.temporal.TemporalAccessor;
import java.util.*;
import java.util.concurrent.locks.ReentrantLock;

public class Solution {
    public static void main(String[] args) throws IOException{
        Reader.init(System.in);
        long h = 973303; long c  = 519683 ; long t = 866255;
        double lol = (double)(h-t) /(double) (2*t - h - c);
        for (int i = 0 ; i < 15 ; i++){
//            System.out.println(i +" " + ((i+10)%15));
        }
//        System.out.println(lol);
        t =Reader.nextInt();
//        t =1;
//        System.out.println(cnt);
        PrintWriter out = new PrintWriter(System.out);
        int i = 1;
        while (t-->0){
//            out.print("Case #" + i + ": ");
            solve(out);
            i++;
        }
        out.close();
    }
    static class Pair{
        int l , r;

        public Pair(int l, int r) {
            this.l = l;
            this.r = r;
        }
    }
    static LinkedList<Integer>[] g;
    static boolean[] v;
    static TreeSet<Integer> set = new TreeSet<>();
    static int[] c;
    static void solve(PrintWriter out)throws IOException {
        int n = Reader.nextInt();
        int m = Reader.nextInt();
        g = new LinkedList[n+1];
        for (int i = 0 ; i <= n ; i++){
            g[i] = new LinkedList<>();
        }
        c = new int[n+1];
//        c[0] = new LinkedList<>();
//        c[1] = new LinkedList<>();
        int ok = -1;
        v = new boolean[n+1];
        for (int i = 0; i < m ; i++){
            int n1 = Reader.nextInt();
            int n2 = Reader.nextInt();
            g[n1].add(n2);
            g[n2].add(n1);
            ok = n1;
        }
        c[ok] = 0;
        dfs(1);
        int cnt0 = 0;
        int cnt1 = 0;
        for (int i = 1 ; i <= n ; i++){
            if (c[i]==0) {
                cnt0++;
            }
            else{
                cnt1++;
            }
        }
//        System.out.println(Arrays.toString(c));
        if (cnt0>cnt1){
            out.println(cnt1);
            for (int i  = 1 ; i <= n ; i++){
                if (c[i]==1){
                    out.print(i+" ");
                }
            }
        }
        else{
            out.println(cnt0);
            for (int i = 1 ; i<= n ; i++){
                if (c[i]==0){
                    out.print(i+" ");
                }
            }
        }
        out.println();
    }

    static void dfs(int cur){
        Deque<Integer> q = new LinkedList<>();
        q.addLast(cur);
        v[cur] = true;
        while (q.isEmpty()==false){
            int s = q.removeFirst();
            Iterator<Integer> i = g[s].iterator();
            while (i.hasNext()){
                int nxt = i.next();
                if (!v[nxt]){
                    v[nxt] = true;
                    c[nxt] = 1 ^ c[s];
                    q.addLast(nxt);
                }
            }
        }
    }

    static int gcd(int a, int b)
    {
        if (b == 0)
            return a;
        return gcd(b, a % b);
    }

    static void sieveOfEratosthenes(int n)
    {
        // Create a boolean array "prime[0..n]" and initialize
        // all entries it as true. A value in prime[i] will
        // finally be false if i is Not a prime, else true.
        boolean prime[] = new boolean[n+1];
        for(int i=0;i<n;i++)
            prime[i] = true;

        for(int p = 2; p*p <=n; p++)
        {
            // If prime[p] is not changed, then it is a prime
            if(prime[p] == true)
            {
                // Update all multiples of p
                for(int i = p*p; i <= n; i += p)
                    prime[i] = false;
            }
        }

        // Print all prime numbers
        for(int i = 2; i <= n; i++)
        {
            if(prime[i] == true){
                set.add(i);
            }
        }
    }




    public static int stringCompare(String str1, String str2)
    {

        int l1 = str1.length();
        int l2 = str2.length();
        int lmin = Math.min(l1, l2);

        for (int i = 0; i < lmin; i++) {
            int str1_ch = (int)str1.charAt(i);
            int str2_ch = (int)str2.charAt(i);

            if (str1_ch != str2_ch) {
                return str1_ch - str2_ch;
            }
        }

        // Edge case for strings like
        // String 1="Geeks" and String 2="Geeksforgeeks"
        if (l1 != l2) {
            return l1 - l2;
        }

        // If none of the above conditions is true,
        // it implies both the strings are equal
        else {
            return 0;
        }
    }








    static int next(long[] arr, long target)
    {
        int start = 0, end = arr.length - 1;

        int ans = -1;
        while (start <= end) {
            int mid = (start + end) / 2;

            // Move to right side if target is
            // greater.
            if (arr[mid] <= target) {
                start = mid + 1;
            }

            // Move left side.
            else {
                ans = mid;
                end = mid - 1;
            }
        }
        return ans;
    }

//    static int find(int x) {
//        return parent[x] == x ? x : (parent[x] = find(parent[x]));
//    }
//    static boolean merge(int x, int y) {
//        x = find(x);
//        y = find(y);
//        if (x==y){
//            return false;
//        }
//        parent[x] = y;
//        return true;
//    }







    public static void sortbyColumn(int arr[][], int col)
    {
        // Using built-in sort function Arrays.sort
        Arrays.sort(arr, new Comparator<int[]>() {

            @Override
            // Compare values according to columns
            public int compare(final int[] entry1,
                               final int[] entry2) {

                // To sort in descending order revert
                // the '>' Operator
                if (entry1[col] > entry2[col])
                    return 1;
                else
                    return -1;
            }
        });  // End of function call sort().
    }



}


class Reader {
    static BufferedReader reader;
    static StringTokenizer tokenizer;

    /** call this method to initialize reader for InputStream */
    static void init(InputStream input) {
        reader = new BufferedReader(
                new InputStreamReader(input) );
        tokenizer = new StringTokenizer("");
    }
    /** get next word */
    static String next() throws IOException {
        while ( ! tokenizer.hasMoreTokens() ) {
            //TODO add check for eof if necessary
            tokenizer = new StringTokenizer(
                    reader.readLine() );
        }
        return tokenizer.nextToken();
    }

    static int nextInt() throws IOException {
        return Integer.parseInt( next() );
    }
    static long nextLong() throws IOException {
        return Long.parseLong( next() );
    }

    static double nextDouble() throws IOException {
        return Double.parseDouble( next() );
    }
}
class Pair{
    int a;
    int b;

    public Pair(int a, int b) {
        this.a = a;
        this.b = b;
    }
}
class MergeSort
{
    // Merges two subarrays of arr[].
    // First subarray is arr[l..m]
    // Second subarray is arr[m+1..r]

    void merge(int arr[], int l, int m, int r)
    {
        // Find sizes of two subarrays to be merged
        int n1 = m - l + 1;
        int n2 = r - m;

        /* Create temp arrays */
        int L[] = new int [n1];
        int R[] = new int [n2];

        /*Copy data to temp arrays*/
        for (int i=0; i<n1; ++i)
            L[i] = arr[l + i];
        for (int j=0; j<n2; ++j)
            R[j] = arr[m + 1+ j];


        /* Merge the temp arrays */

        // Initial indexes of first and second subarrays
        int i = 0, j = 0;

        // Initial index of merged subarry array
        int k = l;
        while (i < n1 && j < n2)
        {
            if (L[i] <= R[j])
            {
                arr[k] = L[i];
                i++;
            }
            else
            {
                arr[k] = R[j];
                j++;
            }
            k++;
        }

        /* Copy remaining elements of L[] if any */
        while (i < n1)
        {
            arr[k] = L[i];
            i++;
            k++;
        }

        /* Copy remaining elements of R[] if any */
        while (j < n2)
        {
            arr[k] = R[j];
            j++;
            k++;
        }
    }

    // Main function that sorts arr[l..r] using
    // merge()
    void sort(int arr[], int l, int r)
    {
        if (l < r)
        {
            // Find the middle point
            int m = (l+r)/2;

            // Sort first and second halves
            sort(arr, l, m);
            sort(arr , m+1, r);

            // Merge the sorted halves
            merge(arr, l, m, r);
        }
    }

    /* A utility function to print array of size n */
    static void printArray(int arr[])
    {
        int n = arr.length;
        for (int i=0; i<n; ++i)
            System.out.print(arr[i] + " ");
        System.out.println();
    }

    // Driver method

}

class Node implements Comparable<Node>{
    int a;
    int b;
    Node (int a , int b){
        this.a = a;
        this.b = b;
    }



    public int compareTo(Node o) {
        if ((this.a%2) == (o.a%2)){
            return (this.b - o.b);
        }
        else{
            return this.a - o.a;
        }
    }
}
class Graph
{
    int V;// No. of vertices

    //An Array of List which contains
    //references to the Adjacency List of
    //each vertex
    List <Integer> adj[];
    public Graph(int V)// Constructor
    {
        this.V = V;
        adj = new ArrayList[V];
        for(int i = 0; i < V; i++)
            adj[i]=new ArrayList<Integer>();
    }

    // function to add an edge to graph
    public void addEdge(int u,int v)
    {
        adj[u].add(v);
    }
    // prints a Topological Sort of the complete graph
    public void topologicalSort(PrintWriter out,TreeSet set)
    {
        // Create a array to store indegrees of all
        // vertices. Initialize all indegrees as 0.
        int indegree[] = new int[V];

        // Traverse adjacency lists to fill indegrees of
        // vertices. This step takes O(V+E) time
        for(int i = 0; i < V; i++)
        {
            ArrayList<Integer> temp = (ArrayList<Integer>) adj[i];
            for(int node : temp)
            {
                indegree[node]++;
            }
        }

        // Create a queue and enqueue all vertices with
        // indegree 0
        Queue<Integer> q = new LinkedList<Integer>();
        for(int i = 0;i < V; i++)
        {
            if(indegree[i]==0)
                q.add(i);
        }

        // Initialize count of visited vertices
        int cnt = 0;

        // Create a vector to store result (A topological
        // ordering of the vertices)
        Vector <Integer> topOrder=new Vector<Integer>();
        while(!q.isEmpty())
        {
            // Extract front of queue (or perform dequeue)
            // and add it to topological order
            int u=q.poll();
            topOrder.add(u);

            // Iterate through all its neighbouring nodes
            // of dequeued node u and decrease their in-degree
            // by 1
            for(int node : adj[u])
            {
                // If in-degree becomes zero, add it to queue
                if(--indegree[node] == 0)
                    q.add(node);
            }
            cnt++;
        }

        // Check if there was a cycle
        if(cnt != V)
        {
            out.println(-1);
            return ;
        }

        // Print topological order
        for(int i : topOrder)
        {
            if (set.contains((char)('A'+i))) {
                out.print((char) ('A' + i));
            }
        }
        out.println();
    }
}
// Driver program to test above functions