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 java.util.*;

import javax.lang.model.util.ElementScanner6;

import java.io.*;

public class Main{

    public static void main(String[] args) {

        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader inp = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Solver solver = new Solver();
        solver.solve(inp, out);
        out.close();
        
        }



    static class Solver {


        class Node implements Comparable<Node>{
            int i;
            long c;
        
            Node(int i,long c)
            {
                this.i=i;
                this.c=c;


            }

        public int compareTo(Node n)
            {
                if(this.c==n.c)
                {
                    return Integer.compare(this.i, n.i);
                }
                return Long.compare(this.c, n.c);
            }
        }

        public boolean done(int[] sp,int[] par)
        {
            int root;

            root=findSet(sp[0],par);
            
        for(int i=1;i<sp.length;i++)
        {
                if(root!=findSet(sp[i], par))
                    return false;
        }
        return true;
        }
    public int findSet(int i,int[] par)
    {
        int x =i;
            boolean flag =false;
            while(par[i]>=0)
            {
                flag = true;
                i=par[i];
            }
            if(flag)
                par[x]=i;
            return i;
    }

    public void unionSet(int i,int j,int[] par)
    {
            int x = findSet(i, par);
            int y = findSet(j, par);
            if(x<y)
            {
                par[y]=x;
            }
            else
            {
                par[x]=y;
            }
    }

    public  long pow(long a, long b, long MOD) {
            if (b == 0) {
                return 1;
            }
            if (b == 1) {
                return a;
            }
            long val = pow(a, b / 2, MOD);
            if (b % 2 == 0) {
                return val * val % MOD;
            } else {
                return val * (val * a % MOD) % MOD;

            }
        
        }


        public void minPrimeFactor(int n,int[] s)
        {
            boolean prime[] = new boolean[n+1];
            Arrays.fill(prime, true);
            s[1]=1;
            s[2]=2;
            for(int i=4;i<=n;i+=2)
            {
                prime[i]=false;
                s[i]=2;
            }

            for(int i=3;i<=n;i+=2)
            {
                if(prime[i])
                {
                    s[i]=i;
                    for(int j=2*i;j<=n;j+=i)
                    {
                        prime[j]=false;
                        s[j]=i;
                    }
                }
            }
            
        }

        
        // public void findAllPrime(int n,ArrayList<Node> al,int s[])
        // {
        //     int curr = s[n];
        //     int cnt = 1;
        //     while(n>1)
        //     {
        //         n/=s[n];
        //         if(curr==s[n])
        //         {
        //             cnt++;
        //             continue;

        //         }
        //         Node n1 = new Node(curr,cnt);
        //         al.add(n1);

        //         curr=s[n];
        //         cnt=1;
        //     }
        // }

        

        public int binarySearch(int n,int k)
        {
            int left=1;
            int right=100000000+5;
            int ans=0;
            while(left<=right)
            {
                int mid = (left+right)/2;
                if(n/mid>=k)
                {
                    left = mid+1;
                    ans=mid;
                }
                else
                {
                    right=mid-1;
                }
            }

            return ans;
        }
        public boolean checkPallindrom(String s)
        {
            char ch[] = s.toCharArray();

            for(int i=0;i<s.length()/2;i++)
            {
                if(ch[i]!=ch[s.length()-1-i])
                    return false;
            }
            return true;
        }


        public void dfs_util(ArrayList<Integer>[] al,boolean vis[],int x,int g,int arr[],int[] count)
        {
                
            vis[x] = true;
            count[0]++;
            arr[x]=g;
          
            // System.out.println("x "+x);
                for(int i=0;i<al[x].size();i++)
                {
                    
                    if(!vis[al[x].get(i)])
                    {
                        // System.out.println("s.size "+s.size());
                        dfs_util(al, vis, al[x].get(i),g,arr,count);   
                        
                    }    
                    
                }

            
              
            
            
            return ;
        }

        public void dfs(ArrayList<Integer>[] al,int arr[],int arr1[])
        {
            
            boolean vis[] = new boolean[al.length];
           
            int g =0;
            int count[]= new int[1];
            
            for(int i=0;i<al.length;i++)
            { 
             
               
                    if(!vis[i])
                    {
                        count[0]=0;
                        dfs_util(al,vis,i,g,arr,count);
                        arr1[g]=count[0];
                        g++;
                        
                       
                    }
                   
            }

           


        }

        public void remove(ArrayList<Integer>[] al,int x)
        {
            for(int i=0;i<al.length;i++)
            {
                for(int j=0;j<al[i].size();j++)
                {

                    if(al[i].get(j)==x)
                        al[i].remove(j);

                }
            }
        }

        public long gcd(long a, long b) 
        { 
            if (a == 0) 
                return b; 
            return gcd(b % a, a); 
        }


        public void printDivisors(long n,ArrayList<Long> al) 
        { 
            // Note that this loop runs till square root 
            for (long i=2; i<=Math.sqrt(n); i++) 
            { 
                if (n%i==0) 
                { 
                    // If divisors are equal, print only one 
                    if (n/i == i) 
                    {
                        
                            al.add(i);
                    }
                      
        
                    else // Otherwise print both 
                    {   
                            al.add(i); 
                            al.add(n/i);
                    }
                        
                } 
            } 
        } 

        public static long constructSegment(long seg[],long arr[], int low,int high,int pos)
        {
            if(low==high)
            {
                seg[pos] = arr[low]; 
                return seg[pos];
            }
            int mid = (low+high)/2;
            long t1=constructSegment(seg, arr,low , mid,(2*pos)+1);
            long t2=constructSegment(seg,arr,mid+1,high,(2*pos)+2);
            seg[pos] = t1+t2;
            return seg[pos];

        }
        public static long querySegment(long seg[],int low,int high,int qlow, int qhigh,int pos)
        {
            
             if(qlow<=low&&qhigh>=high)
             {
                return seg[pos];
             }
             else if(qlow>high||qhigh<low )
             {
                 return 0;
             }
             else{
                long ans=0;
                int mid=(low+high)/2;
                ans+=querySegment(seg,low , mid, qlow, qhigh,  (2*pos)+1);
                ans+=querySegment(seg, mid+1, high, qlow, qhigh, (2*pos)+2);
               return ans; 
             }

        }
        public static int lcs( char[] X, char[] Y, int m, int n ) 
        { 
            if (m == 0 || n == 0) 
            return 0; 
            if (X[m-1] == Y[n-1]) 
            return 1 + lcs(X, Y, m-1, n-1); 
            else
            return Integer.max(lcs(X, Y, m, n-1), lcs(X, Y, m-1, n)); 
        } 

        public static long recursion(long start,long end,long cnt[],int a, int b)
        {

            long min=0;
            long count=0;
            int ans1=-1;
            int ans2=-1;
            int l=0;
            int r=cnt.length-1;
            while(l<=r)
            {
                int mid=(l+r)/2;
                if(cnt[mid]>=start)
                {
                    ans1=mid;
                    r=mid-1;
                }
                else
                {
                    l=mid+1;
                }
            }

            l=0;
            r=cnt.length-1;
            while(l<=r)
            {
                int mid=(l+r)/2;
                if(cnt[mid]<=end)
                {
                    ans2=mid;
                    l=mid+1;
                }
                else
                {
                    r=mid-1;
                }
            }
            
            if(ans1==-1||ans2==-1||ans2<ans1)
            {
                // System.out.println("min1 "+min);
                min=a;
                return a;

            }
            else
            {
                min=b*(end-start+1)*(ans2-ans1+1);
            }
            if(start==end)
            {
                // System.out.println("min "+min);
                return min;
            }
            long mid = (end+start)/2;
            min = Long.min(min,recursion(start, mid, cnt, a, b)+recursion(mid+1, end, cnt, a, b));
            // System.out.println("min "+min);
            return min;
        }

       



      

        private void solve(InputReader inp, PrintWriter out1) {
         
                int t =inp.nextInt();
            for(int k=0;k<t;k++)
            {
                int  n = inp.nextInt();
                int m =inp.nextInt();

                ArrayList<Integer> al[] = new ArrayList[n];

                for(int i=0;i<n;i++)
                {
                    al[i] = new ArrayList<Integer>();
                }

                for(int i=0;i<m;i++)
                {
                    int x = inp.nextInt();
                    int y = inp.nextInt();

                    al[x-1].add(y-1);
                    al[y-1].add(x-1);
                }

                boolean vis[] = new  boolean[n];
                Queue<Integer> q = new LinkedList<Integer>();
                int count[] = new int[2];
                int ar[] = new int[n];
                q.add(0);
                ar[0]=0;
                while(!q.isEmpty())
                {
                    int x=q.remove();
                    for(int i=0;i<al[x].size();i++)
                    {
                        if(!vis[al[x].get(i)])
                        {
                            q.add(al[x].get(i));
                            ar[al[x].get(i)]=1^ar[x];
                            vis[al[x].get(i)]=true;
                        }
                    }


                }
               
                for(int i=0;i<n;i++)
                {
                    count[ar[i]]++;
                }
                ArrayList<Integer> ans = new ArrayList<Integer>();
                if(count[0]<count[1])
                {
                    for(int i=0;i<n;i++)
                    {
                        if(ar[i]==0)
                        {
                            ans.add(i+1);
                        }
                    }
                }
                else
                {
                    for(int i=0;i<n;i++)
                    {
                        if(ar[i]==1)
                        {
                            ans.add(i+1);
                        }
                    }
                }
                out1.println(Math.min(count[0],count[1]));
                for(int i=0;i<ans.size();i++)
                {
                    out1.print(ans.get(i)+" ");
                }
                out1.println();
            }
        }
}





    static class InputReader {
        BufferedReader reader;
        StringTokenizer tokenizer;

        InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

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

        public long nextLong() {
            return Long.parseLong(next());
        }
    }
}
class ele{
    long value;
    long i;
    boolean flag;
    public ele(long value,long i)
    {
        this.value = value;
        this.i=i;
        this.flag = false;
    }
}