import java.util.Scanner;

public class allies
{

    public static void main (String[] args)
    {
    	
    int numCases, numNodes, numEdges;
    int leftnode, rightnode, i, j;
    boolean[][] enemies;
    boolean[] potentialAlly;
    String allyList;


	Scanner scan = new Scanner(System.in);
	numCases = scan.nextInt();
	
	for (int curCase=0; curCase<numCases; curCase++)
	{
		numNodes = scan.nextInt();
		numEdges = scan.nextInt();
				
		//System.out.println("nodes: "+numNodes);
		//System.out.println("edges: "+numEdges);
		
		//initialize enemies list
		enemies = new boolean[numNodes+1][numNodes+1];
		for (i=1; i<numNodes+1; i++)
			for (j=1; j<numNodes+1; j++)
				enemies[i][j] = false;
		
		//initialize ally list
		potentialAlly = new boolean[numNodes+1];
		for (i=1; i<numNodes+1; i++)
			potentialAlly[i]=false;
		
		//read edge set from input
		for (int curEdge=0; curEdge<numEdges; curEdge++)
		{					
			leftnode = scan.nextInt();
			rightnode = scan.nextInt();
			enemies[leftnode][rightnode] = true;
			enemies[rightnode][leftnode] = true;
			//System.out.println(leftnode+" "+rightnode);		
		}//end-for-edge
		
		//set nodes of distance 2 from node 1
		for (i=1; i<numNodes+1; i++)
			for (j=1; j<numNodes+1; j++)
				if (enemies[1][i] && enemies[i][j])
					potentialAlly[j]=true;
					
		// remove nodes of distance 1
		for (j=1; j<numNodes+1; j++)
			if (enemies[1][j])
				potentialAlly[j]=false;
		
		//scan for allies
		allyList = new String();
		for (i=1; i<numNodes+1; i++)
			if (potentialAlly[i])
				allyList += i + " ";

		System.out.println(allyList);
			
		
		
	}//end-for-case
	
	
	
    }//end-main

}//end-class